LEXINGTON, Ky. -- Kentucky's Willie Cauley-Stein was ruled out of Saturday night's game after a "minor procedure" on an old injury to his left knee.

The 7-foot freshman forward did not practice Friday before the Wildcats (11-5, 2-1) left for Auburn and a Southeastern Conference game against the Tigers.

Kentucky spokesman DeWayne Peevy, citing privacy laws, would give no details about Thursday's procedure, including whether it was surgery.

Coach John Calipari said it was an old injury that Cauley-Stein could have played through, but the coaching staff decided to "play it safe" and address it now.

Cauley-Stein had started the Wildcats' past five games and is averaging 7.6 points and 5.8 rebounds in nearly 21 minutes per game this season. His 31 blocks rank third in the SEC.

"It just happened to where, all right, let's go" get it fixed, Calipari said. "But it's all good. We're one short for a short while. Thank God, it was nothing major."

Cauley-Stein played just 15 minutes in Kentucky's 75-65 victory over Tennessee on Tuesday night, his lowest total since logging 13 minutes against Baylor on Dec. 1. In his previous four games -- all starts alongside fellow freshman Nerlens Noel -- he had averaged 24.8 minutes per game.

Cauley-Stein had been playing with discomfort recently, Calipari said.

"There were times where he was like, 'You've got to get me out,' " the coach said. "We had a shootaround the other day and he stopped, and I said, 'What are you doing?' Just walking around. Again, nothing major, just an old thing he never did anything about.

"We could have been, 'You're fine, put the knee sleeve on and go,' but that's not how we operate here. If I err, I'm going to err on the side of the kid. Let's just be safe."

Peevy also said senior reserve guard Twany Beckham is out with a lower back injury. Junior guard Jon Hood returned to practice Thursday from an illness that sidelined him for the past six games.