The Raiders cut quarterback Trent Edwards and season limit of 53.
Edwards was the odd man out at quarterback. The Raiders already have starter Jason Campbell and Kyle Boller, while former Ohio State quarterback Terrelle Pryor was placed on the reserve/suspended list.
Pryor signed with the club last week after being selected in the supplemental draft. He will be forced to sit the first five games of the regular season because of the scandal at Ohio State that forced head coach Jim Tressel to resign.
The veteran Sheppard signed with Oakland a week ago, after spending the 2010 season with Minnesota and appearing in 13 games.
Also cut Saturday was linebacker Sam Williams, who has been with the Raiders since 2003. He has appeared in 84 games (24 starts) and recorded 129 tackles.
They waived tight end Kevin Brock; defensive ends Mason Brodine and Tommie Hill; defensive back Stevie Brown; defensive tackles Jamie Cumbie and Derrick Hill; linebackers Chris Francis, Bani Gbadyu and J Leman; wide receivers Chad Jackson and Eddie McGee; cornerbacks Walter McFadden and Sterling Moore; punter Glenn Pakulak; guard Alex Parsons; running back Louis Rankin; and fullback Manase Tonga.
Wideout Shawn Bayes, guard Roy Shuening and cornerback Jeremy Ware were waived/injured.