ORCHARD PARK, N.Y. -- Pro Bowl defensive end Mario Williams and linebacker Kiko Alonso, who both underwent offseason hip surgery, did not participate in the Buffalo Bills' first organized team activity Wednesday.
Williams was in uniform but remained on the sideline for the duration of the practice.
"We knew that we got [the procedure] done right away so he wouldn't miss any time," coach Doug Marrone said. "We're just being progressive as we work this through camp with him."
Last season, Williams played in all 16 games and tallied 13 sacks, his highest total since 2007. He was added to the injury report mid-season with the hip ailment.
Alonso also was on the sideline. He played on every defensive snap last season and finished second in voting for The Associated Press' defensive rookie of the year award.
Alonso's surgery was to repair a torn labrum and was performed sometime in January, a league source told ESPN's Adam Caplan. The recovery time for such a procedure is typically four to six months.
Alonso is being moved from MLB to WLB position within the 4-3 scheme under new defensive coordinator Jim Schwartz. WLB is typically a more athletic position than MLB, so it's critical that Alonso gets full movement back in his surgically repaired hip.
Alonso, who was a second-round pick last season for the Bills, played in all 1,145 defensive snaps as a rookie.
Wide receiver Robert Woods (ankle surgery), safety Aaron Williams (shoulder surgery), cornerbacks Stephon Gilmore and Leodis McKelvin (both hip surgery), tight end Scott Chandler (knee surgery), and wide receiver T.J. Graham (hip surgery) were among other Bills players not taking part in team drills Wednesday.