LOS ANGELES – It’s always an important game when Arizona and UCLA get together, but having lost three of their last four games and with No. 4 North Carolina coming up next week, this game could determine whether the Wildcats stay among the nation’s elite, at least for the time being.

The No. 11 Wildcats (13-4, 4-3 Pacific 10 Conference) face the un-Arizona-like fate of losing four of five if they cannot upset No. 3 UCLA in tomorrow’s 2 p.m. game in Pauley Pavilion.

“”It’s a must-win,”” said guard Jawann McClellan. “”There’s not too much more to say than we have to go out there and win.””

Getting that split won’t be easy against a Bruins squad (16-1, 5-1) that beat Arizona three times last year, made it to the National Championship game and was ranked No. 1 in the nation earlier this year, but that’s exactly what Arizona might need to do to stay in the thick of the competitive Pac-10.

After losing to USC last night, the Wildcats dropped to sixth in the conference – ground that won’t be made up easily if they fall to .500 in the league and 2.5 games behind the Bruins almost halfway through the schedule.

“”Any game in the Pac-10 you have to take care of your home,”” said forward Marcus Williams, who should be fine tomorrow despite banging his injured left wrist again last night. “”We gave one away at home (in a loss to then-No. 15 Oregon), so we’ve got to win on the road.

“”The Pac-10 is going to be a tight race. It could come down to one or two games, so we’ve got to get all the wins we can.””

For the Bruins it all starts with guard Arron Afflalo, who flirted with entering the NBA Draft after the Bruins’ deep NCAA Tournament run last year before retuning and averaging 16.4 points per game this year, sixth in the conference.

Afflalo, who averaged 24.5 points in the two regular season games against Arizona last year, is also the Bruins’ go-to player in the clutch, nailing the game-winning jumper with four seconds left against USC last week.

“”He’s a great player,”” McClellan said. “”I respect him, but I still need to come out and guard him. We can’t be worried about one player, we’ve got to try and stop the team.””

Point guard Darren Collison has taken much of the hurt out of the loss of All-Pac-10 point guard Jordan Farmar, who left for the NBA after his sophomore season last year. Collison has been the Bruins’ floor general and ranks second in the conference in assists (six per game) and first in 3-point percentage (52.1 percent) and steals (2.44) entering the week.

“”I think they’re kind of similar,”” said UA guard Mustafa Shakur. “”They run the same sets and things like that.””

Guard Josh Shipp returned to UCLA’s lineup last night in their 60-50 win over ASU, scoring 12 points. He had missed last Saturday’s game against USC with a strained hamstring, which UCLA head coach Ben Howland said at the time was a proactive move to make sure the injury did not get worse.

Shipp’s no stranger to injury problems as he missed all but four games with a right hip injury that had to be repaired surgically last year.

“”The whole hamstring issue began because initially, he was cramping,”” Howland said in a conference call earlier this week. “”It weakens the muscle because it’s always under contraction, and it gets to the point where the muscle tears a little bit, so a lot of it has to do with what you put in your body as well as how hard you’re pushing it.””

Howland said potassium is important for the body to prevent cramping, so his staff was reminded Shipp of a certain yellow fruit that’s a large source of potassium.

“”He said, ‘I don’t like bananas.’ So (we said), ‘You’ve got to learn to like them,” Howland said. “”It’s also hydrating. … I was forcing him to drink Gatorade more than he wants to drink because hydration is so important.””

With the Bruins back at full strength, it certainly won’t be easy for the Wildcats to break this losing streak, but UA head coach Lute Olson isn’t worried this early in the season.

“”We just have to solve the problems that have been causing difficulties,”” he said. “”It’s an 18-game schedule plus the Pac-10 Tournament. All that we’re trying to look at is (what) we need to (do to) get better.””