I know one thing for sure-Jarvis Perry is a monster runner and a huge key cog in the cavalier offense. We will sorely miss him for however long he is out. The power dimension to the run game is important to the cavaliers, and on quick hitting inside plays there is hardly a chance that perry wouldn't get at least three yards. He also has underrated speed on the outside stretch play. Very sad to see him go down and i don't think his college career should be jeopardized by rushing back from this injury. While there is certainly no replacing jarvis perry, I do believe terry lyons has a lot of natural ability running the football. He is very, very difficult to bring down, never gives up on a play, and is hardly ever taken down on first contact. He can break tackles, but also has the ability to reverse the field, find a seam, and break a big one. His pass blocking may be the question mark since he hasn't been called on for much pass protection thus far, but running wise and behind a veteran offensive line he is a more than capable backup. Nevertheless, i along with all the other cavaliers hope jarvis' rehab goes well and he is able to return at full strength sooner rather than later. Good Luck Cavs!