Antonio Brown's rise and fall from promising rookie to endless headache for the NFL

Nine years ago, as the Pittsburgh Steelers opened training camp for the 2010 season, head coach Mike Tomlin assessed the future of sixth-round pick Antonio Brown and Brown's fellow rookie receivers.

"The pedigree stands out," Tomlin told the Pittsburgh Post-Gazette. "They show maturity in terms of catching the football and gaining separation ... but they still got miles to go. They're rookies. But I like what they're doing."

Now, nine years later, Brown has separated himself from his rookie class -- and the rest of the NFL -- by fashioning the most prolific six-year stretch for a receiver in NFL history, topping 100 receptions and 1,200 yards receiving in each of the past six seasons.

But Brown's on-field accomplishments have been accompanied by off-field drama so unrelenting that it's had some fans checking their newsfeeds on an hourly basis.

Here's a timeline of recent events surrounding the All-Pro wideout:

JAN. 15, 2017: In the Steelers' locker room after the team's 18-16 playoff win over the Kansas City Chiefs, Brown secretly streams the team's post-game celebration on Facebook Live, including Tomlin's postgame remarks about the Steelers' next opponent, the New England Patriots. Brown is fined for his violation of the NFL's social media policy.

OCT. 9, 2018: Brown faces a pair of lawsuits for an April incident in which he allegedly damaged his leased South Florida apartment and threw items off his balcony that nearly struck a 2-year-old boy.

NOV. 8, 2018: Brown is ticketed for driving more than 100 mph on a suburban Pittsburgh road with a speed limit of 45 mph, after police pull over his black Porsche sports car at 10 in the morning.

DEC. 16, 2018: At a team practice in the week leading up to the Steelers' regular-season finale against the Cincinnati Bengals, Brown gets into a dispute with quarterback Ben Roethlisberger, according to multiple media reports. Brown then skips the week's remaining practices, leading the team to deactivate him for that Sunday's game.

FEB. 12, 2019: In a Twitter post, Brown thanks Steelers fans for the last nine years but says that it's "time to move on," spurring the team to investigate trading the elite receiver, who still has three years left on his contract.

MARCH 10, 2019: The Steelers trade Brown to the Oakland Raiders for a third-round pick and a fifth-round pick in the 2019 draft. Later reports suggest the Patriots may have offered as much as a first-round pick for the discontented wideout, but that the Steelers didn't want to trade him to such a close rival.

JULY 26, 2019: After signing a restructured contract that includes $30 million in guaranteed money, Brown arrives at Raiders' training camp in a hot-air balloon -- but the 10th-year receiver can't practice due to a frostbite injury to his feet caused by a mishap during a recent cryotherapy session.

JULY 30, 2019: Brown practices with the Raiders but leaves the field early when he isn't allowed to wear his helmet of choice because the 10-year-old model is no longer certified safe by the league. After petitioning the league for permission to use the helmet, Brown returns to practice two weeks later but leaves practice the following week after the league rules against him.

SEPT. 4, 2019: Brown posts to Instagram a letter from Raiders general manager Mike Mayock levying $54,000 in fines for Brown's absences from training camp. "When your own team want to hate ... everyone got to pay this year," Brown says in the post. Later in the day he gets into a confrontation with Mayock on the Raiders' practice field before teammates pull him away from the GM, according to several media reports.

SEPT. 6, 2019: Brown offers an emotional apology to his Raiders teammates at a team meeting, prompting coach Jon Gruden to say the team is "really excited" to have Brown on board and that they're "ready to move on" together. Then, later in the day, Brown posts a video to YouTube that includes portions of a private phone conversation Brown recorded between him and Gruden.

SEPT. 7, 2019: The Raiders fine Brown $215,000 for conduct detrimental to the team, thereby voiding Brown's $30 million in guaranteed money. Brown then takes to Instagram to ask for his release, saying, "You are gonna piss a lot of people off when you start doing what's best for you," and, "I'm not mad at anyone. I'm just asking for the freedom to prove them all wrong." Just hours later, the Raiders release him.

SEPT. 8, 2019: The day after being let go by the Raiders, Brown agrees to a 1-year deal with the New England Patriots worth up to $15 million with a $9 million signing bonus. The news comes on the same day that reports surface suggesting that Brown may have sought advice from social media consultants on how to speed up his release from the Raiders.

SEPT. 10, 2019: Brown is accused in a civil lawsuit of sexually assaulting a woman who had been his personal trainer on three occasions between 2017 and 2018. Patriots officials say the league has opened an investigation into the accusations.

SEPT. 20, 2019: After playing just one game for the New England Patriots, Brown is released from the team amid the sexual assault allegations. The Patriots said it was "best to move in a different direction at this time." Brown appeared to confirm the news, writing in a tweet, "Thank you for the opportunity." He later tweeted, "The marathon continues."