As I said before, getting an MRI is getting an MRI. If the training staff wasn't concerned about the possibility of ligament damage they wouldn't have sent him for an MRI.
And Guice dancing and doing whatever in the locker room didn't mean he wasn't hurt. I've had a partially torn ACL for over 5 years now. And when I first tore it I walked down 3 flights of stairs and could of danced if I needed to. It was the next day when I woke up that the ACL announced something was wrong. I was then told when I initially tore it I could rehab with no surgery to strengthen my leg muscles to stabilize my knee and see how it goes or get surgery. I chose rehab without surgery because my ACL is only partially torn and my kids were young, didn't want to leave my wife to deal with 2 young kids while I couldn't walk after surgery. I was also told that I couldn't play "cutting sports" until I get it fixed. So I haven't played organized softball or kickball (don't ask) since. At some point I will need to get it fixed, and it hurts like a SOB after walking a lot, but I am putting off surgery as long as possible.
Anyway, losing Guice after 6 rushes for 19 yards in the 1st pre-season game is brutal.