COSTA MESA, Calif. (AP) - The Los Angeles Chargers have placed rookie receiver Mike Williams on the physically unable to perform list with a back injury.

The Chargers made the move Saturday with Williams, the seventh overall pick out of Clemson.

The team is optimistic Williams can avoid major surgery after he incurred a herniated disk in his lower back during the first day of the Chargers' offseason program.

Williams has responded positively to treatment, Chargers general manager Tom Telesco said Thursday. Los Angeles wants to get Williams on the field at some point during training camp to prepare for his first season.

The Chargers also put cornerback Jason Verrett and safety Darrell Stuckey on the PUP list.