Buffalo Bills wide receiver Sammy Watkins was among 10 players not cleared for the start of training camp on Friday.
Watkins is recovering from April surgery to repair a broken bone in his left foot. Watkins was seen stretching with his teammates on Friday.
The Bills placed Watkins, wide receiver Marcus Easley, defensive end Shaq Lawson and defensive tackle Kyle Williams on the active/physically unable to perform list.
Lawson is recovering from offseason shoulder surgery and Williams underwent knee surgery last season. Easley is recovering from a knee injury.
The team also placed linebacker Manny Lawson and wide receiver Kolby Listenbee on the active/non-football injury list.
In addition, the team has placed defensive tackle Marcell Dareus, defensive back Jonathan Dowling, offensive tackle Seantrel Henderson and running back Karlos Williams on the active/non-football illness list.
Karlos Williams, who showed up for offseason workouts about 25 pounds overweight, has been suspended for the first four games of the season for violating the NFL's substance-abuse policy.