Hartline's leg appeared to get caught in the turf as he was chased by safety Darian Stewart on the Wildcats' first series of the second half on Saturday. Hartline got up and began to hop toward the sidelines when Kentucky trainers caught up with him.
The injury was orginally called a twisted knee. Hartline spent the second half sitting on the sidelines with his knee heavily bandaged and iced. He did not return.
Hartline had thrown a touchdown pass and was 9 of 14 for 139 yards as the Wildcats took a 17-14 halftime lead.
South Carolina rallied to win 28-26.