Houston Texans linebacker Jadeveon Clowney did not participate in team drills Thursday on the first day of training camp.
Clowney, who has been rehabbing from arthroscopic knee surgery, was limited to individual drills, according to the Houston Chronicle.
The former No. 1 overall pick in the 2014 NFL Draft, Clowney played in all 16 games for the first time in his career in 2017.
Clowney, who is entering the final season of his five-year rookie contract and is seeking a new deal, finished with 9.5 sacks and 59 tackles (41 solo) a year ago.
Texans head coach Bill O'Brien told the newspaper that he does not expect Clowney to participate in full contract drills on Saturday.
"Some guys are needing to get back into a little better football shape right now as far as playing football, he comes under that category," O'Brien said. "He'll be ready to go pretty soon. I'm not concerned about him, though. He wasn't able to, because of his rehab and all that, he wasn't able to be in OTAs.
"We're just trying to be intelligent about the way we bring him back."
The 6-foot-5, 270-pound Clowney's 15.5 sacks are tied for 23rd among NFL players since the beginning of the 2016 season, and he has 37 tackles for loss, second to Arizona Cardinals defensive end Chandler Jones.