The only way he's ever run 4.51 in a game is if he got a 5-yard head start.
I watched every Miami snap last year. I've regularly pimped Miami guys that I wanted to see on the Patriots. There are two I didn't. Xavier Restrepo (Makes Chism look like Usain Bolt) and Damien Martinez.
Martinez was the lead back the first four games of the year, after that he lost his starting job to a freshman...who is not currently starting.
Martinez' college numbers last year were inflated thanks to running behind the best offensive line in the country, and lots of zone coverage thanks to Cam Ward at QB.