Selected 19th overall by the Bills in April's NFL draft, Lawson signed his four-year rookie contract with the team on Monday.
Bills general manager Doug Whaley has pegged the defensive end out of Clemson as a Week 1 starter, provided he's not on the physically unable to perform list. Last month, Lawson underwent surgery on his right shoulder in what was described as a preventative procedure by the team.
Lawson, whose shoulder issues were a cause of concern for some scouts at the NFL Scouting Combine in February, said at the time he wouldn't need surgery. NFL Media Insider Ian Rapoport reported in May that Lawson likely will begin training camp on the PUP list and there's a chance he could still be on that list by the time the regular season begins.
"I'm still engaged in meetings and things like that," Lawson said, via the team. "Engaged in practice and watching film. I continue to watch film like I'm still out there playing. I'm taking a lot of mental reps. I'm not physically able to do it, but a lot of mental reps. Seeing things with the older guys, things like that."