At the top of the ladder that is the Pacific 10 Conference, there is little room for missteps.

The No. 12 Arizona baseball team (30-7, 8-1 Pac-10) made its first of the season last weekend at Stanford, handing the Cardinal its first conference win in a 6-3 loss Sunday.

Stanford had already been swept by UCLA – the team Arizona is tied with atop the Pac-10 standings – and ASU, which, at 10-2 in conference, is right on the Wildcats’ and Bruins’ heels.

“”We feel like we kind of let one slip there,”” said pitcher Brad Mills, who will start the second game of this weekend’s series at Washington State (17-17, 1-8 Pac-10), the second of three-straight road series.

The Sunday loss to Stanford snapped a 16-game winning streak, Arizona’s longest since opening the 1998 season 16-0.

“”I told (the team), ‘Our identity is not winning 16 games in a row. Our identity is to get up here and be better today. You should be better today than you were on Sunday,'”” said UA head coach Andy Lopez. “”Everybody here has something to work at.””

Still, the Wildcats, picked fifth by the conference coaches in a preseason poll, are off to their best conference start ever, matching the 2005 team that went to the NCAA Regionals.

“”We’ve put ourselves in a position to where every game here on out is big. We’re not playing catch-up,”” Mills said. “”We’ll have to really blow it to not make a regional.

“”(Lopez) always says he takes the sets of games in sets of 10, and if your last 10 mean something, then you’ve put yourself in a good spot. That’s our goal right now, is just make those last 10 against whoever it is really mean something.””

Mills threw the first complete game of his career last weekend, giving up just one run on seven hits and striking out four in the 15-1 win Saturday.

With his team up big for the second-straight week, the senior southpaw said the difference between his last start (a 15-12 win over California, when he gave up five runs in 5 1/3 innings) and his complete game performance against the Cardinal rested on not trying to do too much.

“”The Cal game, I kind of got caught up in wanting to throw a shutout and a complete game,”” Mills said. “”Even though I didn’t get the shutout against Stanford, I was happy that I was able to go pitch-by-pitch, not worry about the end result, and then all of a sudden, what do you know, I’m in the ninth.””

Mills, who will toe the mound for tomorrow’s 2 p.m. start, is now tied for the conference lead in wins, with eight, and his 62 strikeouts against just 18 walks on the season give him a 3.4 strikeout-to-walk ratio.

Mills’ complete game came after right-hander Preston Guilmet went nine innings for the fourth consecutive time – a span that covers three complete games.

And while Lopez acknowledged “”stretching”” his first two starters, he said it’s been somewhat of a necessity with closer Daniel Schlereth out with torn cartilage in his ribs.

“”We don’t normally do that with our pitchers, except we don’t have Schlereth available,”” Lopez said.

Schlereth will likely miss the series while still recovering from the torn cartilage he suffered while warming up March 28 against ASU.

Though Lopez didn’t expect him back earlier this week, the closer – who has yet to pitch an inning in conference season – has said he expects to return to the bullpen by next weekend at the latest.

Designated hitter Bill Rhinehart practiced yesterday for the first time in two weeks, but he could also potentially miss his second consecutive series with a concussion.

Guilmet (7-0), who leads the Pac-10 in both ERA (1.58) and strikeouts (83), will throw tonight’s 5:30 start opposite Cougars’ righty Wayne Daman (2-2, 3.79 ERA).

Ryan Perry (0-1, 7.36) will throw Sunday for Arizona.