X factors: Emerging game-changers

— -- Seattle Seahawks outside linebacker Malcolm Smith joined a unique club when he hoisted the MVP trophy after Super Bowl XLVIII.

That award seemed reserved for a bigger name when observers contemplated the possibility of Seattle beating Denver that night, someone such as quarterback Russell Wilson, running back Marshawn Lynch or wide receiver Percy Harvin.

Instead, it was Smith who reminded us that it's the role players who sometimes shine brightest in the biggest games. With a 69-yard interception return for a touchdown and a fumble recovery, he became the Seahawks' version of Baltimore's Jacoby Jones , the New York Giants' David Tyree and the Green Bay Packers' James Starks  -- unheralded contributors who played vital parts in the championship runs of their respective teams.

Some call them wild cards. Others call them breakout performers. For the sake of this article, we'll go with this term: X factors. As much as this postseason might hinge on the efforts of stars such as  Tom Brady, Aaron Rodgers or Peyton Manning, recent history suggests that the people who operate below the radar should command our attention as well.

"It's that happy-go-lucky guy on the team who isn't thinking about what it might be like to play in front of 85,000 people or have a game broadcast to 110 countries," said Oakland Raiders defensive end Justin Tuck. "It's the unknown player who understands the importance of not making the games bigger than what they are."

Tuck was one such player. He blossomed into a devastating pass-rusher who registered two sacks and a forced fumble in the Giants' upset win over the New England Patriots in Super Bowl XLII. It was in that same game that Tyree -- a special-teams ace who had four receptions all season -- made an improbable 32-yard, third-down catch against his helmet to keep his team's game-winning touchdown drive alive.

In more recent years, Starks emerged as an unlikely star, fueling Green Bay's running game when the Packers went on to beat Pittsburgh in Super Bowl XLV, while Jones delivered an assortment of big plays during the Ravens' Super Bowl run in the 2012 season (including a game-tying, 70-yard touchdown catch in a divisional playoff win over Denver and two touchdowns in the Super Bowl against San Francisco).

There are plenty of candidates for breakout stars in this season's playoffs. The only question is which ones will actually deliver.

"I wish I could tell you who those guys are, because I'd be a general manager someday if I could," Tuck said. "All I know is that some people have a knack for it, and some people don't."

Here are five players who just might have such a knack:

Martavis Bryant, WR, Pittsburgh Steelers

Pittsburgh Steelers wide receiver Martavis Bryant strolled into the team facility on an ordinary Saturday morning in mid-October, his mind focused mainly on a walk-through practice for the next day's game against Houston. It wasn't until Bryant ran into head coach Mike Tomlin that he realized his NFL career was about to change for the better. Tomlin told Bryant he'd been impressed by what the rookie had shown during six weeks on the scout team. In fact, Bryant had been so good that Tomlin was suiting him up for his first professional game that weekend.

It was a moment that could've left Bryant nervous or giddy. Instead, he saw it as the culmination of everything he'd gone through to earn his coach's trust. "Coach Tomlin had told me that he wanted me to dominate on scout team before he would give me a hat [a chance to play]," Bryant said. "Once he gave me the opportunity, I told him that I wasn't going back there."

So far, Bryant hasn't given the Steelers any reason to regret that decision. In a season when rookie receivers have dominated like no other, he's carved his own niche with a Steelers offense that has been as explosive as any unit in the league. Bryant has only 26 receptions on the season, but he's averaged 21.1 yards per catch and scored eight touchdowns. Six of those scores came in his first four games, and opponents quickly learned to not underestimate his abilities.

Bryant brings great size (6-foot-4, 211 pounds) to the Steelers' receiving corps along with startling speed for a player that big (he ran the 40-yard dash in 4.42 seconds at the league's scouting combine in February). Add him to a group that already includes Pro Bowl wideout  Antonio Brown, Lance Moore and Markus Wheaton and it's easy to see why the Steelers ranked second in the NFL in passing offense. "He has great size and great speed," said Steelers receivers coach Richard Mann. "You can't teach those things. He's really been able to stretch the field for us."

Bryant's success also has plenty to do with the Steelers' approach to handling him. He entered the league as a fourth-round pick out of Clemson -- where he was overshadowed by Buffalo's Sammy Watkins, the fourth overall pick in the 2014 draft -- and he was too raw to immediately step into the Pittsburgh offense. Immaturity and inconsistency had limited Bryant's playing time to the point that he caught only 19 passes in his first two seasons in college. It wasn't until his junior season in 2013 that he began to shine, amassing 42 receptions, 828 yards and seven touchdowns.

Mann said the Steelers chose to bring Bryant along slowly because "sometimes players lose their confidence if you throw them to the wolves. We didn't want to give him too much at once." Bryant admits that playing on the scout team wasn't the path he envisioned for himself -- a preseason shoulder injury also set him back -- but he made the most of the opportunity. He worked on route running, ball skills, blocking, releases and anything he was asked to do. Before long, he was taking screen passes and racing past baffled first-team defenders for touchdowns -- exactly what Tomlin had hoped to see.

Bryant already has produced some big highlights for the Steelers -- he had an 80-yard touchdown against the Jets and a 94-yard score against the Bengals -- but he understands that more will be needed in a wild-card matchup against Baltimore. The Ravens certainly will try to contain Brown, which will leave Bryant with opportunities to shine. It helps that teammates have counseled him on how the intensity rises at this time of year. But Mann also believes Bryant has benefited from playing in a couple of late regular-season games that had a playoff feel because Pittsburgh was chasing the AFC North title.

Regardless of the advice Bryant has received, he already knows there's still more for him to prove in his first season. "I'm sure a lot of people still don't know who I am," Bryant said. "But I also think that the more I work at this, the more success will come my way."

C.J. Anderson, RB, Denver Broncos

They descended upon him in a crowded tunnel outside the cramped locker room inside O.co Coliseum in Oakland, California. There were aunts and admirers, cousins and coaches, people who knew Broncos running back C.J. Anderson when he was trying to make a name for himself in Pop Warner. They all came to congratulate him on his first NFL start, a 41-17 win over the Raiders, the same team he had grown up watching as a native of Vallejo, California.

But with all those loved ones celebrating Anderson's 163 total yards and one touchdown that afternoon, it was a comment offered by Broncos defensive end DeMarcus Ware that stuck with Anderson. "You've done it for one week," Ware said. "Now you have to do it again."

What Anderson couldn't know at that time was how critical those words would be to Denver's playoff hopes. Back then, the Broncos were just happy to know a player who had all of 24 carries before that Oakland game could contribute after the team lost starter Montee Ball and second-string back Ronnie Hillman to injuries. Today, there's a different narrative hovering around the Broncos. It involves the sudden struggles of Pro Bowl quarterback Peyton Manning and an offense that sorely needs Anderson to keep supplying the boost he's given Denver's running game.

It's a challenge that seems appropriate for a player who has been fighting for an opportunity since going undrafted in April 2013.

"I always play with a chip on my shoulder because of that," said Anderson, who played his college ball at Cal. "It was hard [to not be drafted], and eventually I got a phone call to come here. But I also wear No. 22 for a reason. That's because 22 other running backs were selected in that draft, and I wasn't."

Anderson has proved over the past two months that overlooking him was a huge mistake. After an off week following the Oakland game, he hit his stride with 27 carries for 167 yards and a touchdown in a win over Miami on Nov. 23, followed up by 168 yards on 32 attempts in a victory at Kansas City.

Just as surprising was Anderson's three-TD effort in Denver's 24-17 win over Buffalo on Dec. 7, which marked the first time in 52 games Manning hadn't thrown a touchdown pass.

Those performances were the first indication that Anderson -- who has 849 rushing yards and eight touchdowns this season -- might be more than another back playing in Manning's shadow. Keyed by Manning's inconsistency and injuries to other players, the Broncos' pass-crazy offense underwent a noticeable late-season makeover, with brutality and balance becoming as essential as finesse and fast pace.

As Anderson said, "I think I bring nastiness with my running style. I have some wiggle, but I run tough. If I see a linebacker in the hole, I want to let him know I'm going to be hard to deal with all day. And I'm going to punish defensive backs when I get the chance."

"The big thing about C.J. is that he doesn't want to be a one-dimensional back," said Broncos running backs coach Eric Studesville. "He can be elusive. He can catch the ball and run after the catch. And he's been good in pass protection. He's proving that he's an all-around back."

The major testament to Anderson's ability is the trust that Manning has put in him. The Broncos' offense relies on all players communicating about what they see, and Manning often asks Anderson to keep an eye on defensive adjustments the quarterback might miss before the snap. Anderson believes his football IQ helps him have Manning's back in such situations. When Anderson wasn't getting snaps, studying his playbook was the best way for him to stay positive about eventually playing a bigger role.

Now that the day has arrived, Anderson is eager to help the Broncos return to the Super Bowl.

"We have a lot of playmakers on this team," Anderson said. "I'm a great example of that because I was a third-string running back, and I've been able to do some things. Our mindset is that it doesn't matter if it happens through the run or the pass. We are going to make things happen."

Brandon LaFell, WR, New England Patriots

Patriots wide receiver Brandon LaFell thought he was having a simple post-practice conversation in June, when he strolled toward the locker room with fellow receiver Julian Edelman following a minicamp session. Instead, he received a dose of insight that would serve him well in the coming weeks. Edelman wanted to know how LaFell's previous team, the Carolina Panthers, handled the receivers on the depth chart from week to week. When LaFell told Edelman that the Panthers did the same thing every other team did -- basically that everyone knew who was a starter and who was a backup -- Edelman chuckled. "He told me we don't really have starters here," LaFell said. "We get after it in practice, and then we see who ends up on the field on Sundays."

LaFell could've felt a heightened sense of urgency after that talk, especially since he admittedly struggled to keep up with all the assignments New England's coaches threw at him during offseason workouts. He wound up doing the opposite, displaying impressive patience and finding a way to stand out on a team that sorely needed another receiver to evolve in its offense. The main reason LaFell seems destined to be a key performer for New England this postseason isn't merely the fact that he's playing with Brady. It's because he's raised his stock with each passing month this season.

LaFell signed with the Patriots after they gave him a three-year, $9 million contract that trumped the one-year deal Carolina offered him. With career highs in receptions, yards and touchdowns, he's given the Pats what they expected.

"It definitely took a while to get going," LaFell said. "I missed part of OTAs with an injury. Then I started training camp working with the twos before rotating in with the ones. And I didn't really establish a chemistry with Tom until we played Kansas City [a 41-14 loss in Week 4]. But ever since that time, we've really been on the same page."

LaFell was one of the few bright spots for the Patriots in that loss to the Chiefs, as he produced six receptions for 119 yards and a touchdown. It was also a huge game for him because he didn't catch a single pass in New England's first two contests. Now he's become a trusted target for Brady, a 6-foot-3, 210-pound weapon who can capitalize when defenses devote too much attention to covering Edelman and Pro Bowl tight end Rob Gronkowski.

As Patriots head coach Bill Belichick recently told Boston radio station WEEI: "[LaFell] uses his size to create separation, and he's hard to tackle, using his body to catch the ball in tight spaces. ... We love the way he's brought those things to our team."

The postseason should afford LaFell more opportunities to impress his head coach.

LaFell spent his first four pro seasons in Carolina and helped that team win the NFC South in 2013. Although the Panthers lost to San Francisco in the divisional round, LaFell said he learned how important it is to raise his intensity this time of year.

"The speed of the game is definitely different in the playoffs," he said. "And you have to be ready to play at that level."

Coby Fleener, TE, Indianapolis Colts

They met at Stanford six years ago, a strapping, fleet-footed tight end known for being a late bloomer and a once-in-a-lifetime quarterback prospect who made people envision the second coming of John Elway.

Coby Fleener was only a true freshman at the time, but he did understand the mission he was given by his college coaches: Sell quarterback Andrew Luck on joining the program during his official visit. Looking back on that moment, Fleener still wonders how much impact he had on Luck's future that weekend. Even then, it seemed as if the quarterback was traveling a predetermined path, one that would lead through Stanford and on to the riches of the NFL.

In contrast, Fleener, in his third season as a tight end with the Colts, always seems to travel along an unpredictable path.

The same player who once quit football after his freshman year at Joliet Catholic High in Illinois -- and didn't imagine himself as a potential NFL player until deep into his college career -- has now blossomed into the consistent threat the Colts envisioned when they made him the first tight end selected in the 2012 draft. As was the case in college, Fleener's presence was overshadowed by Luck, the first overall pick in that class. But much like in college, the longer Fleener has played with in the NFL, the more he's proved how valuable he can be to an offense.

It's not just the career highs in receiving yards and touchdowns that portray his emergence this season. It's his consistency, a decline in dropped balls, improved blocking and a spike in big plays.

It's taken a couple of years for Fleener to find his groove in the NFL, but he's definitely located it at the right time. As Colts offensive coordinator Pep Hamilton said recently, "Coby has passed the 'up-and-coming' stage of his career."

"Having a great team is a big part [of my success]," Fleener said. "And I'm enjoying the opportunity to be in this position. There are certain things that have happened that have allowed me to shoulder more of the load in this offense."

One of those factors was a midseason injury that sidelined fellow tight end Dwayne Allen for two games and part of a 42-20 loss to New England on Nov. 16. Fleener produced seven receptions for 144 yards in that Colts defeat, then added another four catches for 127 yards and two touchdowns in a 49-27 win over Washington two weeks later. For a pass-heavy offense that already has a Pro Bowl receiver in T.Y. Hilton, it was exciting to see another big-play threat emerge at a time when the productivity of longtime star wideout Reggie Wayne has suffered.

Fleener might not be as versatile a pass-catcher and blocker as Allen, but his size (6-foot-6, 251 pounds) and speed (he runs the 40 in the 4.5-second range) make him dangerous in other ways.

What makes Fleener scarier these days is his burgeoning confidence level. He's lined up in Hamilton's offense for two seasons in Indianapolis and a year at Stanford (where Hamilton was the Cardinal's offensive coordinator during Fleener's senior season in 2011). Fleener said he knows the nuances of the offense so well that he helps Luck teach it to teammates. Fleener admits that he struggled to grasp the offense of former coordinator Bruce Arians as a rookie, and it slowed his development.

Said Hamilton: "I wasn't here for his first year, but I think he was overthinking things. That first year brings a big learning curve for everyone. If you're always thinking about what you have to do, it's going to slow you down. He's up to speed now."

That is critical for the Colts' offense, because Fleener is sure to see more targets in the postseason. His success against New England and Washington came largely because those defenses chose to cover him one-on-one. If that happens again, Fleener expects to be ready.

"That's what you play the game for -- those one-on-one matchups," he said. "You know what's coming, the quarterback knows it and so does the defender. And it's up to you to be able to make those plays."

John Brown, WR, Arizona Cardinals

Cardinals wide receiver John Brown heard the invitation, but he couldn't quite believe it.

The rookie had just finished his first offseason training program with the team when quarterback Carson Palmer invited him to spend two weeks at his home in San Diego for more intensive work. Brown already knew that Palmer was a fan; the quarterback had sent Brown a congratulatory text after the Cardinals selected the Pittsburg State product in the third round of the 2014 draft. Now Palmer wanted to help the young talent get his career moving in the right direction as soon as possible.

As surprised as Brown was by the request, he's grateful that Palmer took such an early interest in his career. Those rigorous daily workouts -- which included heavy doses of route running, coverage recognition and weightlifting -- put Brown on the fast track to understanding life in the NFL. In a draft class that has featured more breathtaking rookie receivers than any in history, Brown has provided plenty of evidence of what he can do when the ball is thrown in his direction. The next step in his development is proving what he can do when the games matter more than ever.

It's no secret that that the Cardinals' offense has been sputtering in the second half of the season, particularly because the quarterback position has been plagued by injuries to Palmer (on injured reserve with a torn ACL) and backup Drew Stanton (out indefinitely, also with a knee injury). But as much as people wonder how head coach Bruce Arians will do in the playoffs with that uncertainty under center, another key question is whether Brown can help fellow receivers Larry Fitzgerald and Michael Floyd make enough big plays to ease the pressure on whomever is starting.

"There's certainly more pressure on me now, because the coaches know what I can do," Brown said. "They expect something big. And that's what I live for."

Brown said he was shocked when the Cardinals drafted him last May. He didn't think there was any way a team would spend a third-round pick on a 5-foot-10, 179-pound receiver from a Division II school.

At 24 years old, Brown's road map to the NFL had been marked by detours and pain: a year at tiny Mars Hill College in North Carolina, a year spent out of football, another year lost to a redshirt at Coffeyville Community College in Kansas, and then the murder of his half-brother James Walker before his All-America career started at Pittsburg State in 2011. Given the way his life had played out, Brown was grateful for even the tiniest bit of faith in his potential.

Brown never lost sight of the importance of capitalizing on opportunities. He caught a 13-yard touchdown pass from Palmer in the season opener against San Diego. Two weeks later, he scored twice in a win over San Francisco, and his 75-yard touchdown reception beat Philadelphia a month later. By Week 10, Brown had made league history: No first-year player ever had produced four game-winning touchdown receptions in one season.

"He's really a dynamic player," said Cardinals receivers coach Darryl Drake. "He has the speed, the quickness and really good hands. We saw those qualities when we drafted him, and we knew it didn't matter what size he was or what school he went to. The big thing for him is that he hasn't let anybody down."

"My size was always a big detraction when people looked at me," said Brown, who grew up in Homestead, Florida. "When I was in Florida, none of the big schools down there really wanted me because they felt there were players better than me. But if you look around the NFL now, none of those players are here. People didn't believe in me, but I always thought I had a chance."

That mindset will be critical as Brown heads into his first postseason.

The Cardinals have used him mainly as an outside receiver, and he's responded with 48 receptions, 696 yards and five touchdowns. With bigger receivers such as Fitzgerald and Floyd drawing more coverage, he'll be asked to be just as impactful in the playoffs as he was during the regular season.

He still gets timely bits of insight from Palmer -- even as the quarterback rehabs his knee -- and his coaches don't think the playoff pressure will make him wilt.

"John grew up in a tough environment, and he's gone through some tough things," Drake said. "The game isn't too big for him. No stage is too big for him."