ORCHARD PARK, N.Y. (AP) - Vowing to put his troubled past behind him, offensive guard Richie Incognito expressed his gratitude on Monday for an opportunity to revive his career with the Buffalo Bills.

''There were a lot of things said and done that I wish I could change,'' Incognito said after the Bills opened their voluntary offseason conditioning program. ''I think I can use this situation to shed light on a sensitive subject, as well as kind of put my best foot forward and show that I have grown and have learned from this situation.''

Incognito was contrite while speaking with a large group of reporters for the first time since signing a one-year contract with the Bills in February. It also marked Incognito's first opportunity to discuss in detail what he learned during a 15-month stint away from football as result of his involvement in the Miami Dolphins' bullying scandal in 2013.

''It was frustrating,'' Incognito said. ''But I think at the end of the day, humbling is the best way to describe it.''

Now, the eight-year veteran is working on proving himself while understanding his every move will be scrutinized, and acknowledging that not everyone will be quick to give him the benefit of the doubt.

''I definitely have a lot to live up to,'' Incognito said. ''Nobody's perfect. And I think the biggest thing is I've learned from what I went through, learned from what went down. And I've grown from it, so that's where I'm at.''

Incognito was suspended for the final eight games of the 2013 season, when the Dolphins were thrust into the spotlight after offensive lineman Jonathan Martin abruptly quit the team amid accusations he was being bullied. An NFL investigation determined Incognito and two other Dolphins offensive linemen persistently harassed Martin, who played for San Francisco last season.

Though re-instated by the NFL a year ago, Incognito was rejected in several bids to sign with other teams until being approached by the Bills this offseason.

And the Bills didn't sign Incognito until he had a face-to-face interview with owners Terry and Kim Pegula, general manager Doug Whaley and new coach Rex Ryan.

''What's in the past is in the past. You learn from it,'' Ryan said Monday. ''Some things that you did wrong, maybe you wish you did differently. I know that's how I'm looking at it: moving forward.''

Incognito is a 2012 Pro Bowl selection with a reputation for being a solid run blocker as well as being one of the NFL's dirtiest players.

Listed at 6-foot-3 and 319 pounds, he has started each of his 102 career games since being selected in the third round of the 2005 draft by St. Louis. He also had a brief stint in Buffalo during the 2009 season when the Bills claimed him after he was waived by the Rams.

The Bills are retooling their offense with a run-first approach under Ryan and incoming coordinator Greg Roman.

''I know what I bring to the team,'' Incognito said. ''I want to come in and help make these guys around me better. I want to earn a starting spot. And definitely, I want to prove myself.''

Incognito declared himself to be ''in great shape,'' and said he focused much of the past 15 months on working out in hopes of one day landing a job.

It wasn't easy.

''There were some dark days where I didn't think I was ever going to play again, and it really fueled me to work hard,'' Incognito said. ''It really forced me to go back and really look at things and say, Is this still important to you? Is this still what you want?' And the answer was always a resounding,Yes.'''

NOTES: Ryan announced a lengthy list of players who won't be fully cleared for practice once the team's spring sessions open with a voluntary veteran minicamp on April 28. The group includes receiver Sammy Watkins, who is coming off hip surgery, as well as defensive backs Stephon Gilmore, Leodis McKelvin and Aaron Williams. Ryan said the players are expected to be cleared for the start of training camp this summer.