The junior beat out the team's top returning rusher in senior Allen Bradford for the job.
Tyler missed all but one game last season due to a toe injury, but is in his best shape in years after dropping 15 pounds since spring ball.
He rushed for 198 yards and a touchdown in limited duty as a freshman.
Freshmen Robert Woods, a receiver, and Nickell Robey, a cornerback, also have earned starting roles. Sophomore Devon Kennard beat out returning starter Chris Galippo for the starting middle linebacker spot.