South Florida 59, Charleston Southern 0
The Bulls (3-0) were ahead 28-0 late in the second quarter when Grothe was hurt. He was tripped from behind by defensive tackle David Jackson, then was falling forward when he was jolted by defensive back Antwain Harvey.
Grothe, the Big East's career leader in total offense, completed 11 of 14 passes for 149 yards and two touchdowns, including a 50-yard strike to Carlton Mitchell. The quarterback also rushed five times for 24 yards, the longest for 9 on the play that sidelined him.
Redshirt freshman B.J. Daniels stepped in for Grothe, matching him with a 50-yard scoring pass to Dontavia Bogan.
A.J. Toscano was 13-for-24 for 127 yards with one interception to lead Charleston Southern (0-3).