Because the season is over, the Sharks have released some info on the injuries. Besides Marleau's MCL sprain, here are a few that Pollak over at WTC thought were the most serious/curious. Days is reference to how long the player has had the injury.

Rob Blake — foot contusion, 10 days, MRI possible.
Jonathan Cheechoo — MCL sprain, left knee, 22 days.
Travis Moen — hip contusion, 8 days.
Douglas Murray — left shoulder may need MRI, acts like mild rotator cuff strain.
Evgeni Nabokov–strained hip muscle (gluteus medius), 13 days.
Joe Pavelski — knee contusion, 4 days.
Devin Setoguchi — mild ankle swelling by Achilles tendon.
Jody Shelley — possible MRI for neck and shoulder soreness.
Joe Thornton–groin/hip flexor, 63 days.