ORCHARD PARK, N.Y. (AP) -- Seantrel Henderson listens to his weaknesses from the NFL's pre-draft scouting report on the offensive tackle, and there are no signs of any discomfort or anger.
''Underachiever traits,'' the report reads. ''Suspect maturity, dependability and decision-making.''
The criticisms are nothing new. Henderson was dealing with them well before Buffalo selected him in the seventh round out of the University of Miami.
''I don't really think about what anybody really said,'' Henderson said, referring to the pre-draft assessment. ''I know who I am. And I know what I can do. And I know what I can be.''
Henderson is not hiding from the mistakes that sidetracked what had the makings of a promising career. Four years ago, he drew comparisons to NFL star tackles Jonathan Ogden and Orlando Pace, while being regarded as one of the nation's top recruits coming out of high school in St. Paul, Minnesota.
Today, he's grateful to have a shot at playing professionally after acknowledging that marijuana use led to him being suspended several times at Miami, and also confirming he tested positive again for marijuana at the NFL combine in February.
Henderson insists that's behind him.
''I feel like in college, I had a lot of maturing to do, sir,'' he said during a three-day rookie minicamp that ended on Monday. ''But at the same time, I have no regrets. I'm happy where I'm at. I wouldn't change it for anything, sir. I'm happy to be here in Buffalo.''
It's in Buffalo where Henderson can begin focusing on what's ahead, while appreciating he's run out of second chances.
''I know for a fact this is the last chance I've got, sir,'' Henderson said. ''I've been through it all in my past four years at the University of Miami. And I know this is the last chance that I've got to be successful. So I won't let it go.''
Henderson ends most every answer with ''sir,'' a trait that dates to college.
What's new is the pat answer Henderson has begun to lean on when confronted with questions about how much he has to prove.
''I've got to prove that I can work as hard as any other guy here, be on time at all times and gain trust with the coaches,'' he said. ''Being accountable, reliable and dependable does that.''
The Bills have been upfront with Henderson.
''We've talked to Seantrel, and he knows that he's got one shot,'' general manager Doug Whaley said. ''He's been dealing with some demons. Hopefully, those demons are out of his life. And why not give somebody - this is America - a second chance.''
At 6-foot-7 and 331 pounds, Henderson has the frame, skill and nimble footwork of someone capable of exceling at tackle.
There were times at Miami where Henderson showed glimpses of his potential.
He earned freshman All-American honors. Last year, he was credited with 10 blocks that resulted in touchdowns, and was invited to the Senior Bowl.
And yet, there are the off-field concerns, some of which Henderson had little control over.
In July 2012, Henderson mourned the loss of his best friend, Jordan Hughes, who was shot and killed in St. Paul. A few days later, he sustained a concussion after being involved in a car accident. In 2011, Henderson had surgery to repair a nagging back problem.
Questions, however, have been raised over his passion for football.
Bills coach Doug Marrone, a former offensive lineman, is keeping an open mind.
''It's early. It really is. And for me, consistency is the thing. I think over a period of time we'll know,'' Marrone said. ''There is no doubt that he can play. The problem is going to come into can he be consistent enough and disciplined enough and have the structure to be a pro.''
Henderson has plenty of reasons to be motivated, including his 2-year-old daughter and his mother.
''I wake up in the morning, and the first thing I think about is my daughter and my mom, and these are people I feel that I have to provide for,'' Henderson said. ''If I don't, then who else will?''
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