LOS ANGELES -- USC opens spring football Tuesday with a rash of injuries that could hinder what the second-year coaching staff is hoping to accomplish, coach Lane Kiffin said Monday.
The Trojans already had a diminished roster due to NCAA sanctions and Kiffin said 20 players have yet to be cleared by doctors for full contact.
"It was just a very unusual amount of offseason surgeries and injuries, unfortunately," Kiffin said.
The offensive and defensive lines and the linebacking position are particularly impacted. Starting guard Khaled Holmes (neck stingers) and potential starters Kevin Graf (shoulder) and Abe Markowitz (foot) have yet to be cleared to practice, as have key linebackers Chris Galippo (lower back), Devon Kennard (hip surgery) and Shane Horton (hip injury).
Also, Kiffin said, defensive linemen Armond Armstead (undisclosed illness), Wes Horton (foot) and Christian Tupou (knee surgery) won't be available at the start of practices. Neither will second-year receiver Kyle Prater (foot), who is in the mix for a starting spot opposite Robert Woods.
Kiffin expects the Trojans to practice in 7-on-7 drills instead of full-squad scrimmages much of the spring due to the injuries.
The lack of experience on the offensive line is of particular concern to Kiffin. Senior center Kristofer O'Dowd and junior tackle Tyron Smith are moving on to the NFL, while center Michael Reardon decided to retire early.
"That's a gigantic issue, the offensive line," Kiffin said. "It's important for anybody, but especially a team built on running the ball. We lose a center who has played a ton of games here, a starting guard who went into private business and a starting right tackle who, I think, is going to be a first-round pick. That's a lot to replace."
Mark Saxon covers USC for ESPNLosAngeles.com.