TAMPA, Fla. — The Tampa Bay Buccaneers placed running back Carnell "Cadillac" Williams on the reserve physically-unable-to-perform list, meaning his bid to return from a serious knee injury will be delayed at least until after the sixth week of the regular season.

In trimming the roster to 75 on Tuesday, the Bucs also put cornerback Sammy Davis (hip) on injured reserve and waived receiver Paris Warren and two injured players, linebacker Antoine Cash (neck) and safety Dante Nicholson (knee).

If Cash, taken from the field on a stretcher after colliding with a teammate making a tackle during Saturday's preseason loss to Jacksonville, and Nicholson clear waivers, they automatically will be placed on IR.

Williams, the 2005 Offensive Rookie of the Year, missed most of 2007 after tearing the patellar tendon in his right knee in September. While he's optimistic about the prospect of playing this season, the earliest he will be eligible to come off PUP is the seventh week of the season.