He is slow, he is weak, and he is dumb
will get caught using banned substances in the NFL multiple times just to stay on a roster
Remember that huge drop in weight (13 pounds?) and his weak bench press... and his slow time despite being lighter...
If i had to bet, I'd guess he was on the gas during that time of the year when he was doing well... probably got "off" after the last regular season game... and that's why he was entirely average against Alabama.
As a pro, he'll have to use to keep up.