Northwestern quarterback Clayton Thorson has a torn anterior cruciate ligament in his right knee, throwing his future up in the air.

The school said Tuesday he will work with the athletic training staff to prepare for surgery in mid-January. There was no timetable for his return.

Thorson announced last month he would return for his senior season. He was then injured catching a pass on a trick play during a win over Kentucky in the Music City Bowl on Friday. Thorson came up clutching his right knee after being tackled and left the field on a cart.

Coach Pat Fitzgerald said after the game that the preliminary exam indicated no serious injury. Subsequent tests revealed a tear.

Thorson’s 27 victories are the most by a Northwestern QB.

Snyder coming back

Kansas State coach Bill Snyder will be back next season.

The 78-year-old coach told his assistants during a short meeting Tuesday that he will return for his 27th season with the Wildcats, a person familiar with his decision told the Associated Press. The person spoke on condition of anonymity because Snyder has not announced his plans.

Snyder said after a Cactus Bowl victory over UCLA last week that he was still mulling whether to return next season or retire for a second time. He stepped away briefly after the 2005 season.

Snyder was diagnosed with throat cancer last offseason, but hardly missed a practice and headed into the year with high expectations. A series of early losses scuttled Big 12 title hopes, and it took a run at the end of the year to become eligible for a bowl game.

Auburn RB declares

Auburn tailback Kerryon Johnson has decided to skip his senior season and enter the NFL Draft. The Southeastern Conference offensive player of the year announced his decision Tuesday in a Twitter post.

Johnson ran for 1,391 yards and 18 TDs this season despite missing two games with injury. He had a three-game SEC stretch when he scored 11 touchdowns.

Johnson ran for 167 yards in an upset of Georgia, which topped the playoff rankings at the time. He had 30 carries for 104 yards against then-No. 1 Alabama, but was limited in the SEC championship game rematch with the Bulldogs by a shoulder injury.

Extra points

In other draft declarations: Oregon State running back Ryan Nall has decided to declare with a year of eligibility remaining, as has Nebraska offensive lineman Nick Gates. Meanwhile, Wisconsin All-America linebacker T.J. Edwards is returning for his senior season.

... Utah hired former Oregon State coach Gary Andersen as an associate head coach and defensive assistant.

... Pitt defensive coordinator JoshConklin was named head coach at Wofford.