Receiver Ronald Johnson was the offensive star for most of USC's spring practice, showing improved route running and a knack for getting open and making big plays.
The senior from Michigan, however, will probably sit out the remaining four workouts because of an elbow sprain and could also require off-season wrist surgery, Coach Lane Kiffin said Thursday.
"We'd still like to have him out there, but if there was somebody that would be the most ready to play for our offensive players, he would be it," Kiffin said.
Johnson was productive, and sometimes spectacular, on short, medium and long-range routes throughout the first three weeks of workouts before suffering the elbow injury early in last week's scrimmage. If he undergoes wrist surgery, it would be similar to the procedure quarterback Matt Barkley had in January, Kiffin said.
Barkley has participated in every spring workout and has said he feels no ill effects in the aftermath of the surgery.
Johnson's absence opens the door for more opportunities for third-year sophomore Brice Butler, freshman Kyle Prater and others competing for playing time in the fall.
Butler contrasted his style with Johnson's.
"I'm kind of like a gazelle, I guess you could say," Butler said. "He's more like a cheetah."
The Trojans practiced with only six offensive linemen, but Kiffin is not concerned that the workload will hurt those still on the field.
"If they're completely exhausted by the end of spring, they've got a long time to recover," Kiffin said. "We can't slow down the rest of our team for one position group."
Redshirt freshman Kevin Graf has played both tackle spots and guard while nursing a condition that is affecting his right shoulder.
"It's a little rough but I like it," Graf said. "This is what we need; this is where we learn everything."
No USC players were chosen in the first round of the NFL draft. The last time the Trojans were shut out in the first round was in 2007…. Running back Dillon Baxter sat out most drills because of a knee sprain…. Max Nikias, who will succeed Steven Sample as USC's president in August, attended practice.