Arizona senior forward Luke Walton isn't expected to play Sunday against Texas and won't practice this week because of a badly sprained right ankle, Wildcats associate head coach Jim Rosborough told ESPN.com on Wednesday.

"Right now, we want to get him ready for the Pac-10 and be good and healthy,'' Rosborough said. "He's probably questionable for the LSU game (Dec. 21) because we want him to be ready for the Pac-10.''

Walton's latest sprained ankle comes less than three weeks after his first sprained ankle limited him to four minutes in a win over Northern Arizona Nov. 27. Walton was well enough to get back on the court for the last two games against Saint Louis and at San Diego State. But he played only 19 minutes against Saint Louis (on point, seven assists and four rebounds) and 24 minutes against the Aztecs (7 points, three rebounds).

Rosborough said freshmen Hassan Adams and Andre Iguodala will replace Walton in the lineup.

"This Texas game is what we need,'' Rosborough said. "We need a big game to give us a good measuring stick.''

"It's really frustrating for him,'' Arizona coach Lute Olson said Wednesday. "You can see him getting back into playing shape and all of a sudden it hits him again. Ankles are always a problem once somebody sprains them. A lot of times they don't heal until after the season is over. He's very, very frustrated by it.''

Walton isn't the only Wildcat ailing. Guard Salim Stoudamire is still nursing a number of injuries. But Rosborough said Stoudamire practiced Wednesday and will play against the Longhorns.

"It's not possible for him to get into the type of condition that he needs to have,'' Olson said. "That really becomes a case of not being able to do much about it and waiting until he's ready to go full.''

Walton was a preseason Wooden award candidate and a favorite for Pac-10 player of the year.

"Luke is so critical to us, so vital in terms of his leadership and passing,'' Olson said. "He's been shooting the ball well. You have to have lift on your shot, or it's not going to be very effective. He had just gotten to the point where his shot was looking good, and was getting good lift on the jump. It will just take some time.

"There is no way you can get ready to play basketball without playing basketball,'' Olson said. "That's the problem. We've done all of the conditioning away from the court that can be done. You have to practice.''

Andy Katz is a senior writer at ESPN.com.