Marqise Lee, who is one of the best players in the country, left practice at USC on Friday after sustaining an apparent shoulder injury, according to Gary Klein of the Los Angeles Times.
The star playmaker, who won the Biletnikoff Award in 2012 as the best receiver in college football, was hurt when he caught a long pass from quarterback Cody Kessler and landed on his right shoulder after being hit by a defender.
After he was attended to by trainers, he was escorted from the field through a gate to the adjoining baseball stadium, and he was later seen nearby shirtless and with his right arm in a sling.
Trojans head coach Lane Kiffin said he did not have an immediate update on Lee's condition.
The junior receiver owns or shares 22 USC records, with marks that include nearly 3,000 receiving yards, 25 touchdowns and two scores on kickoff returns.
USC opens its season August 29 at Hawaii.
Dave Miller, the college football editor and writer for the National Football Post, is on Twitter @Miller_Dave.