HOUSTON, TX (WCMH/AP) – A person familiar with J.J. Watt’s condition said the Houston Texans’ star defensive end has had back surgery and will begin training camp on the physically unable to perform list.

The person spoke to The Associated Press on Thursday night on condition of anonymity because the team hasn’t confirmed the surgery or roster status.

NFL’S Ian Rapoport reported the injury is a herniated disc, and an 8-week return is the best case scenario.

Watt, the NFL sacks leader last season with 17 1/2, will miss the start of training camp, but is expected to be ready for the season opener. He has never missed a regular-season game.

But another NFL Network reporter says the recovery time could be even longer. The Texans are set to open the season on September 11 against the Bears.

The 27-year-old Watt played last season with a herniated disk and spent most of the offseason recovering after having surgery to repair a groin injury in January.

Last season, Watt helped the Texans to their first playoff berth since 2012 and won his second straight Defensive Player of the Year Award. In his 80 straight games in the NFL, he’s had 74.5 sacks and 12 fumble recoveries. That’s more than any other player during that same time frame.

The surgery was first reported by the Houston Chronicle and ESPN.The Associated Press contributed to this report.