The UA coaching staff will continue to sift out who will play important roles in this season’s rotation in the annual Red-Blue Game tonight at 7 p.m. in McKale Center. Admission is free with a Zona Zoo pass or $5 for general-admission tickets.

However, the squad will be without one of its top players in sophomore Marcus Williams, who suffered a “”reasonably severe”” ankle sprain in practice Tuesday, according to UA associate head coach Jim Rosborough.

Williams has never hurt that ankle before, so Rosborough hopes the injury will heal quickly and that he will return to practice Monday.

Even without Williams, who was slated to play with the upperclassmen, the game will likely match primarily underclassmen against upperclassmen, although UA head coach Lute Olson said Tuesday he was not exactly sure of the matchups.

“”Everybody’s trying to keep their minutes,”” McClellan said. “”Everybody’s willing to do whatever it takes to get out there and show the coaches what they need to show in order to get out there and play. I think that makes us better as a team. Everybody’s going hard against each other, hard every day in practice, it just makes everybody else better.””

Olson expects the upperclassmen to be represented by seniors Mustafa Shakur, Ivan Radenovic and Kirk Walters – who’s back after he hit his head Oct. 18 following a concussion suffered Oct. 2 – juniors Jawann McClellan and Daniel Dillon and sophomore Mohamed Tangara.

The underclassman squad is expected to have junior Bret Brielmaier, sophomores J.P. Prince and Onobun and freshmen Chase Budinger, Nic Wise and Jordan Hill. Sophomore David Bagga will play with both teams.

Olson said the game, which will be played with regular officials and with game uniforms, will help get the squad accustomed to what they will see in the regular season, especially to start the year Nov. 12 at Virginia.

“”Like on Saturday (in a scrimmage), we had some guys get in trouble or what would have been foul trouble,”” Olson said. “”We would have had them on the bench. We need to see that in a game situation out there to see who can defend well and not foul.””

With the coaching staff breaking down the contest and evaluating eventual playing time on not just the Red-Blue Game but also play in all the scrimmages and practices the past few weeks, the players know how critical this time is if they want to see the floor.

“”It’s going to be interesting to see how everything plays out,”” McClellan said. “”Coach always says at the beginning of every year how he has depth, so when we go into the Pac-10 season, the rotation is going to narrow down, so we just need let things play out.””

Olson said the competition has been great offensively but that some players are behind on the defensive end.

“”Frankly that’s what’s going to make a difference as to who’s on the court,”” he said.

Onobun, who Olson said will focus primarily on playing power forward after switching between both forward spots last season, said he knows what he needs to show the coaches: running the floor and getting the offense started through rebounding.

As the Wildcats use the Red-Blue Game and a pair of exhibitions to get their rotation set for the start of the season, Onobun said he’s excited for the season to begin.

“”With the Red-Blue Game to start it off, it kind of lets you know that the season is right around the corner,”” he said. “”We’ve been practicing really, really hard. We’ve got a great team, lot of depth. We’re going to be fun to watch this year.””

Shakur and Williams were named to the John R. Wooden Award Preseason All-American team yesterday, as announced by the award’s preseason selection committee.

The Wooden Award is given annually to college basketball’s player of the year and also requires athletes to maintain a 2.0 grade point average and be making progress toward graduation.

Arizona is one of nine schools in the nation to have multiple players on the 50-person list, which includes seven players from the Pacific 10 Conference.

Shakur, a guard, averaged 11.2 points and 4.7 assists per game last season.

Williams, a forward, averaged 13 points and 4.7 rebounds on his way to making the Pac-10 All-Freshman team.

This marks the first time either player has earned this honor.

– Roman Veytsman contributed to this report.