4. St. Louis Rams wide receivers: Since 2011, the Rams have invested five draft choices in the fourth round or higher on wide receivers. They also added Kenny Britt, who looked decent in organized team activities and at minicamp. Tavon Austin offers Harvin-type speed and versatility. Starters Austin Pettis and Chris Givens have to compete against Britt, Brian Quick and Stedman Bailey, who will miss the first four games because of a suspension. The Rams have to sort out the playing time for these pass-catchers.
5. Denver Broncos tight ends: Julius Thomas is emerging as a star. He caught 65 passes in 14 games last season with 12 touchdowns. The plan is for him to be used in creative plays. What makes this competition so interesting is how deep the team is at tight end. Virgil Green, a seventh-round pick in 2011, is also a player whose talents are on the rise. The Broncos also have two other proven tight ends -- Joel Dreessen and Jacob Tamme. The Broncos kept all four tight ends on the roster last year, but are they willing to keep Dreessen and Tamme at nearly $3 million a year if Green emerges?
6. San Francisco 49ers backup halfback: The early word out of San Francisco is that Frank Gore might get 50 fewer carries this year. He had 276 last year. The debate is which back can claim a good portion of those opportunities as the backup. Jim Harbaugh drafted Marcus Lattimore and gave him last season to recover from a devastating knee surgery in college. The 49ers couldn't resist using a second-round pick on Carlos Hyde this year when he fell to them. The Hyde-Lattimore battle may be under the radar, but the winner could tip off what the future looks like in the backfield. Gore is 31 and in the final year of his contract.
7. Buffalo Bills backfield: The Bills have a nice one-two punch with C.J. Spiller and Fred Jackson. In this year's draft, the Bills surprised everyone by trading for Bryce Brown. While Brown might be projected for only 50 carries this season, how he does in camp might reflect on the future of the Bills' backfield. Spiller and Jackson are both free agents at the end of the season. Plus, Jackson is 33. Brown is under contract for one more year. If the Bills don't re-sign Spiller, Brown could end up being a starter next season.
8. New England Patriots wide receivers: Tom Brady started camp last year with Julian Edelman being the only carryover from the receiver corps of the past. Brady staked his fortunes on Edelman, oft-injured Danny Amendola and three rookies -- Aaron Dobson, Kenbrell Thompkins and Josh Boyce. This year's camp will be easier and more competitive. Bill Belichick brought in veteran Brandon LaFell to give the offense one more option. Dobson is considered to be a leader for one of the outside starting jobs, but everything is up for grabs in this camp.