When one of Tiger Woods' best friends already is predicting that the world's No. 1 golfer won't be the favorite at next year's Masters, it speaks volumes about the seriousness of his back injury.

Notah Begay, Woods' college teammate at Stanford, went on CBS radio on Monday and said he thought Tiger's surgery to repair a pinched nerve in his back will keep him out 90 days minimum, CBSSports.com reported.

Woods is recovering from back surgery and did not play in the Masters.

"I've been in contact with him this week," Begay said to CBS radio on Monday. "He missed being at Augusta and certainly was watching the tournament, (but) I think he needs to give (his back) a minimum of 90 days to make sure that scar tissue heals up appropriately and he doesn't run the risk of re-injuring it. So that would push him past the U.S. Open."

Woods played in four PGA events in 2014, finishing in the top 25 just once. Twice, back spasms ruined his chances of winning an event. Once, he quit before finishing the tournament - at the Honda Classic.

"It's like just having a constant toothache for 24 hours a day," Begay said on The Morning Show. "You can't sleep. You can't really get comfortable in any position - seated or lying down. I think he's just at the point where something needed to be done."

Begay's own golf career was cut short by back injuries.

Another CBSSports.com report said the British Open takes place in 94 days , and so Woods' appearance there also is in serious doubt.

And even when Woods comes back, Begay said he doesn't know how Tiger's back will allow him to play.

"I don't know what Tiger's going to be like when he comes back, but Bubba Watson will probably be the favorite heading into next year's Masters," Begay said.

If Tiger is healthy in 2015, will he be the Masters favorite next year? Comment below or tell us @SportsWN.