USC linebacker Porter Gustin is expected to miss several weeks with a torn meniscus in his left knee, multiple media outlets reported.
Gustin was injured during Tuesday's practice and had to be carted off the field. He will undergo surgery after an MRI exam revealed the damage to be a partially torn ligament, the Orange County Register reported, citing a source.
"He was not in a lot of pain," Trojans coach Clay Helton told reporters after Tuesday's practice. "It felt funny to him."
Gustin was limited to four games as a junior last season as he dealt with a fracture toe and torn biceps. He had three sacks in his first three games before the injury bug hit.
The 6-foot-5, 255-pound Gustin has appeared in 28 games in three seasons with the Trojans, recording 14.0 sacks and 23 tackles for loss.