Pittsburgh quarterback Eli Holstein was carted off the field with an air cast on his left leg in the first quarter of Saturday's eventual 37-9 loss at Louisville.
Holstein appeared to have his leg rolled up on when Cardinals defensive lineman Ashton Gillotte sacked him on the second drive of the game.
Holstein did return to the sideline by halftime.
Coach Pat Narduzzi said afterward that the QB was "banged up" but did not elaborate on his status, saying only, "he was out there on the field in the second quarter as well as the whole second half, so we'll see."
Nate Yarnell, who started when Holstein missed last week's game against Clemson with a concussion, replaced him Saturday.
Holstein, a transfer from Alabama, won the starting quarterback job over Yarnell during fall practice and helped lead the Panthers to a 7-0 start.
Pitt has lost four in a row and closes the season next week at Boston College.