MILWAUKEE -- Interim manager Cecil Cooper's roster will expand by six beginning on Tuesday, and he has a loose plan in terms of how he's going to distribute playing time through the final 24 games of the season.

A lot will be dependent on whom the Astros are playing. If they're facing a contender, Cooper is leaning toward using a lineup of regulars, whereas when they're playing teams out of the race, he'll mix in a couple of kids here and there, to give them some big league experience.

The Astros play only two non-contending teams the rest of the way -- the Pirates (Sept. 14-16) and the Reds (Sept. 25-27). The rest of the series are against teams fighting for playoff spots -- the Brewers, the Mets, the Cardinals and the Braves.

Cooper, a former five-time All-Star and Gold Glove winner, understands the importance of maintaining the integrity of the game, and he's also looking forward to playing the spoiler for a few of these playoff hopefuls. That's why he'll use his regulars more often than not.

"We owe it to those guys to go with the lineup we've always gone with," Cooper said, referring to games against contenders. "There might be a case where Cody Ransom plays. He's not a kid. We might find a situation for him. [Humberto] Quintero, he's not a kid, neither is Jason Lane."

But for the rest of the September callups -- J.R. Towles, Juan Gutierrez and Felipe Paulino -- they'll be eased into the mix, just as Josh Anderson was during the recent Cubs series.

Rotation issues: Troy Patton probably will be a sideline observer for the remainder of the road trip, as Cooper will stick with his more veteran trio to face the Mets this weekend in New York.

Wandy Rodriguez is slated to open the series at Shea Stadium on Friday, followed by veterans Roy Oswalt and Woody Williams, both of whom will pitch every five days, despite the six-man rotation.

Patton, who impressed Cooper with his first two big league outings, will probably make his next start when the Astros return home to Houston next week.

"New York -- that's a difficult setting to be in," Cooper said. "Sometimes it's good to let a kid watch some of that and get used to that. We want to make sure veteran guys go in that series. [Patton will] get more opportunities. He'll get at least a couple more starts. We'll see how it goes."

Speaking of Patton: The recent performances of several young pitchers have caught the eye of the Astros' brass lately, but Patton's solid outing against the Cubs on Saturday really stuck out in Cooper's mind in the early morning hours the next day.

Patton, who turned 22 on Labor Day, allowed three runs -- two earned -- over six innings on Saturday. Although he has started his big league career with two losses, he's made quite a positive impression on the decision makers.

"I thought my young pitcher grew up a little bit yesterday," Cooper said on Sunday. "That was a tough situation to be in -- a wild Chicago crowd. He did a good job. That was a real big step for him. He's looking more and more like someone you can count on for next year. That's good for the Astros and for the organization."

Debut: Anderson made his big league debut on Sunday with a pinch-hit appearance at Wrigley Field, and even though he struck out, the outfielder was understandably excited after the game.

"I was getting loose, and I didn't know if I was going to the outfield first or hitting," Anderson said. "[Cooper] said I'd be hitting right away. It's a good thing. I didn't have time to sit around and be nervous and think about it.

"It was great. I felt good. It wasn't as nerve-wracking as I thought it would be. I thought I'd be more nervous than I was."

Coaching callups: In addition to six players arriving from the Minor Leagues, the Astros will add one coach and one athletic trainer to the mix this weekend.

Triple-A Round Rock manager Jackie Moore and Express athletic trainer Mike Freer will join the team in New York on the off-day Thursday and are expected to remain with the club for the rest of the month.

Moore, currently in his 51st season in professional baseball, recently completed his third year as manager of the Round Rock club. He's been a manager in the Astros' organization for eight seasons, and interestingly, he was Cooper's first pro manager, for the Red Sox's short season Class A Jamestown club in 1968.

Freer is in his 18th season with the Astros' Minor League system. In 2003, he was named Minor League Athletic Trainer of the Year by his peers.

Record day: Hunter Pence tied two Astros rookie records on Monday, both of which were previously set by Lance Berkman in 2000 and Luis Gonzalez in 1991.

Pence tied the Astros' rookie doubles record with his 28th of the season, and his eighth-inning triple marked his 50th extra-base hit this year.

Coming up: The Astros and Brewers will meet again at Miller Park on Tuesday, beginning at 7:05 p.m. CT. Right-hander Brandon Backe will make his first big league start of the 2007 season, and he'll face Milwaukee right-hander Carlos Villanueva (6-3, 4.68 ERA).