Los Angeles Chargers first-round WR Mike Williams may need season-ending surgery

Los Angeles Chargers first-round pick Mike Williams reportedly may need back surgery that would end his rookie season.

The team still is hoping Williams will respond positively to a recent second epidural on his herniated disk in a last-ditch effort to have the wide receiver ready at some time during training camp, league sources told ESPN's Adam Schefter on Wednesday.

Williams, 22, was diagnosed with a herniated disk in the lower back after his first practice during rookie minicamp last month and did not practice again. It is unclear if the injury took place before minicamp.

Chargers coach Anthony Lynn told reporters then that he hoped resting Williams' back would allow him to be ready for training camp.

"This may be a lot more serious than people thought," a source told ESPN.

The Chargers are counting on the 6-foot-4, 218-pound Williams to be an immediate contributor. The No. 7 overall selection in this year's draft caught 98 passes for 1,361 yards and 11 touchdowns last season as a key member of Clemson's national championship team.