Ohio State running back Ja'Kobi Jackson underwent foot surgery, a source confirmed to ESPN.

On Tuesday, Buckeyes offensive coordinator Arthur Smith declined to give a timetable for Jackson's return. A source told ESPN that the procedure will cause him to miss "a few weeks," though the hope is that he could return this season.

Jackson suffered the injury Oct. 10 against Maryland. He sat out last weekend's game at Indiana.

Jackson has 354 rushing yards and six touchdowns this season, averaging 6.0 yards per carry.

With Jackson out, sophomore Bo Jackson will likely shoulder more of the rushing load. He carried the ball 18 times against the Hoosiers.

Ohio State coach Ryan Day said Tuesday that the Buckeyes are planning to be without quarterback Julian Sayin for the rest of the season. Sayin suffered an injury to his throwing arm at Indiana. True freshman Luke Fahey will compete with sophomore Tavien St. Clair for the starting job to replace him.

Ohio State has a bye week this weekend. The Buckeyes travel to No. 16 USC on Oct. 31.