I generally am willing to discount supposed 'injury history' and am generally a Freddy fan, mostly since I had him as a rookie. I get attached to my rook's who perform well. If a guy is healthy, he's healthy. If he is coming back from an injury that others have been hindered by, I am wary. Players definitely have different tolerances for pain and the ability to play thru it, and that may affect my player rankings a bit.
That said, I wouldn't take him until the 3rd round. The draft would have to go very wrong for me to take him even at the end of the 2nd round. 4th round? Sure, I probably have 2 RB by then anyway. he is certainly worth the risk for that payoff.
There are guys I stay away from to a point, but if they fall far enough, they usually are worth the gamble.
The meek ain't gonna inherit $#!%....'cuz I'll TAKE IT!