Posted by ESPN.com's Brian Bennett
The junior is expected to be ready for the Sept. 5 opener against Nevada.
"You can practice and play (with the injury)," Weis told reporters. "But the practicing and playing is not completely at full speed. If you get it fixed today, he will be at full speed (by the opener)."
The 6-foot-5 Kamara has started 14 games in his career, including nine last season when he had 20 catches for 206 yards.
Hamilton also is reporting that starting cornerback Darrin Walls is being held out of practice with a tweaked hamstring, but the injury is not considered serious.