TUCSON, Ariz. -- Luke Walton's ankle injury will prevent him from playing Saturday at LSU, and possibly sideline the Arizona star until the Pac-10 opener in January.

He sprained his right ankle for the third time this year nine days ago during practice. He sat out the No. 1 Wildcats' 73-70 victory over Texas on Saturday. Arizona opens conference play on Jan. 2 at Oregon.

By missing the LSU game, Walton will be able to attend Arizona's winter graduation ceremony. The fifth-year senior will receive his bachelor's degree in family studies.

"Getting my degree has always been a goal of mine," Walton said. "Since I'm not going to play Saturday, this is something I really wanted to do. Graduating is a big deal for me."

Walton's father, former NBA and UCLA star Bill Walton, his mother Susan, and his three brothers all will attend. His two older brothers also have their college degrees and his youngest brother, Chris, is in his third year at San Diego State.

"I can't even begin to say how proud we are as parents to see Luke achieve his main goal in coming to the University of Arizona," Bill Walton said. "Education is the No. 1 key to success, and we've been ecstatic with the progress Luke has made at the U of A."