The status of Ohio State star defensive end Nick Bosa has been in doubt ever since he left Saturday's win over TCU in the second half. That status became clear on Thursday, and it's not good news for the Buckeyes.

Coach Urban Meyer said on 97.1 The Fan on Thursday that Bosa underwent surgery to repair a core muscle and will be out indefinitely.

Bosa went to the locker room following the injury, and returned in street clothes as the Buckeyes closed out the win over the Horned Frogs. The star junior -- who is projected to be a first round draft pick after this season -- has a team-high 14 tackles, six tackles for loss and four sacks this season.

The 6-foot-4, 263-pounder was a first-team AP All-American prior to the season, and the centerpiece along the defensive line. With Bosa out, Dre'Mont Jones will likely take over that role until further notice.

Ohio State hosts Tulane this weekend in coach Urban Meyer's first game back after a three-game suspension. The Buckeyes go on the road to Penn State on Sept. 29 in a key Big Ten East battle.