From UCLA:

The following players will not be participating in Spring Practice while rehabbing from surgery/injuries. All are expected back for Fall camp.

QB Darius Bell: Off-season surgery on left shoulder (labrum).
DE Keenan Graham: Off-season surgery on left hip.
OG Casey Griffiths: Back issues.
S Dalton Hilliard: Off-season surgery on right knee to remove loose body.
CB Anthony Jefferson: 2010 surgery broken left foot.
WR Jerry Johnson: 2010 surgery on left ankle fracture.
LB Patrick Larimore: 2010 surgery on left shoulder (labrum).
P Jeff Locke: Off-season surgery on right hip (labrum).

Here are the players who will be limited to non-contact participation. All are expected back for Fall camp.

QB Nate Crissman: 2010 right shoulder surgery (labrum)
WR Shaquelle Evans: 2010 season surgery on left shoulder.
LB Jared Koster: 2010 season surgery on right shoulder
QB Kevin Prince: 2010 right knee surgery (individual drills only)

Here are injured players from last season who have been cleared to participate in Spring Practice.

DE Derrick Bryant: Right shoulder
F-back Robert Franco: Left shoulder
LB Todd Golper: Back
DE Datone Jones: Foot
C Kai Maiava: Left ankle
DB Brandon Sermons: Leg
DE Iuta Tepa: Right shoulder
F-back Damiem Thigpen: Right shoulder
TE John Young: Left shoulder.