Keith Appling has become one of the premier point guards in the Big Ten this season. (USATSI)
Keith Appling has become one of the premier point guards in the Big Ten this season. (USATSI)

When healthy, Michigan State is certainly one of the favorites to win the national championship. But no team has been bitten by the injury bug more than the Spartans this season. 

Adreian Payne returned for Thursday's win over Penn State -- but word came down before the game that point guard Keith Appling was out with a wrist injury.

And now head coach Tom Izzo isn't sure when Appling will return.

"I have no idea," Izzo said, according to MLive.com. "This has been the most frustrating. It's beyond disgusting. I have no timeframe. I know he won't practice tomorrow. Whether he does on Saturday or plays Sunday or whether we're going (to Wisconsin) without him. I wish I could tell you. If I knew, I'd tell you."

Prior to Thursday, Appling hadn't missed a game during his four years in East Lansing. The wirst injury stems from an awkward landing in early December against North Carolina. According to the report, the injury has been re-aggravated multiple times.

"I can't tell you what it was like yesterday," Izzo said. "I'm sitting in my office preparing for practice. I talked to Keith the night before and it sounded like things were getting better. Then the trainer calls and says, 'He can hardly move his wrist.'"

Appling, a 6-foot-1 senior from Detroit, has developed into one of the better point guards in the country. He is the catalyst for Michigan State, pushing the ball in transition and utilizing ball-screens in the half-court. This season, he is averaging 15.0 points and 4.9 assists while shooting better than 40 percent from 3-point range.

Michigan State (20-3 overall, 9-1 in the Big Ten) travels to Wisconsin on Sunday.