CLAIRE C. LAURENCE/Arizona Daily Wildcat Pitcher John Meloan and the rest of the Wildcat baseball team look to make a push for the postseason starting this weekend, when the Wildcats travel to the Bay area to face California and Stanford.

With 12 Pac-10 games remaining this season, the Arizona baseball program knows that it's time to make a push for a playoff bid is running out.

"I hope they sense the immediacy of playing well every weekend," said head coach Andy Lopez. "We don't have to go out and sweep the next five weekends, but we definitely cannot go out and not play well. We need to go out and win, probably two out of three."

The Wildcats (21-18-1, 5-7 Pacific 10 Conference) travel to Berkeley, Calif., this weekend for a three-game series against California (23-25, 7-11). The first game begins today at 2:30 p.m. and the series continues tomorrow and Sunday with 1 p.m. starts.

Junior Koley Kolberg will start today for Arizona. Kolberg (6-3) picked up the loss April 23 at Washington after throwing a complete game but giving up six runs.

Washington swept Arizona in a three-game set last weekend. It was the first time the Wildcats were swept in conference play this year.

Two of the three losses to the Huskies came in Washington's last at-bat - something the Wildcats have become all too familiar with this season.

In Sunday's game, Arizona relinquished an eight-run lead and lost on a walk-off home run in the bottom of the 10th inning.

"It's hard to forget about. I can't believe we lost that game," said junior second baseman John Hardy. "We're going to have to use it to motivate us this weekend."

Of the Wildcats' seven Pac-10 losses this year, four have been within one run, and five have come down to the game's final inning.

The Wildcats lost to Oregon State earlier this season on a two-out RBI single in the bottom of the ninth. They lost twice to UCLA in the final inning - once when the Bruins scored four runs in the ninth and again when Arizona was unable to plate a run with the bases loaded in the ninth.

The trend has both players and coaches asking questions.

"That's the thing that wears on you most," Lopez said. "It's so within grasp that you have a lot of margin to say, 'What if?'"

With Arizona losing five of its last six Pac-10 games, the Wildcats have found themselves in a hole as the season winds down.

"Our backs are against the wall," Hardy said. "There's not a lot of room for error."

Arizona stands seventh in the Pac-10, trailing second-place Washington by three games.

Hardy said he believes the team would have to finish the year by winning eight out of its last 12 games to have a chance at playing in the postseason.

That will be no easy task. Two of Arizona's last four opponents are ranked, including No. 2 Stanford.

After this weekend's series, the Wildcats will stay on the road for a three-game, non conference series against UCLA. The Wildcats and Bruins played their Pac-10 series earlier in the year, with UCLA winning two of three games.