PITTSBURGH -- With center fielder Michael Bourn sidelined with a strained oblique muscle, Jason Bourgeois has an opportunity to show what he can do. Bourgeois started his fifth consecutive game in center field Friday.

After going 0-for-5 on Monday in Washington, Bourgeois had five hits in his next 12 at-bats heading into Friday's game, during which he singled and scored in his first at-bat.

"I want to leave that lasting impression and leave it all out there on the field," Bourgeois said. "I'm trying to take advantage of the last few days."

Bourgeois, a native Houstonian, is a free agent at the end of the season.

"I would love to come back here," he said. "It's the No. 1 place I went to be. The role I would be in would be a fourth outfielder coming off the bench, and I'd rather do it here at home. I haven't talked to them yet, but we'll see when the season ends. I'm playing right now and am focusing on that and will deal with the rest later."

Bourn holds out some hope of returning

PITTSBURGH -- Astros center fielder Michael Bourn said he might have played his final game of the season. Bourn was out of the starting lineup for the fifth consecutive game Friday because of a strained right oblique muscle suffered Sunday.

Bourn is unable to run, much less do any baseball drills. So he spent batting practice Friday at PNC Park watching from the top step of the dugout, dealing with the reality his season could be over.

"It's a chance," he said. "I hope I'm able to, but at the same time I'm not going to rush it either. I'm going to play it by ear. I'm going to get up in the morning and not try to do anything strenuous. The next couple of days or so I'll try to get out and run and see if I can still feel it. Hitting will be probably the last thing I do. From there, we'll see what happens."

The injury came at a terrible time for Bourn, who was hitting .356 with 11 RBIs and 13 stolen bases in his 27 games prior to getting injured. He had reached base in 27 consecutive games since Aug. 21, the longest streak by an Astros player since Lance Berkman's 28-game streak in 2007.

"That's how it happens sometimes," Bourn said. "You can't do anything about it. I just take it as it comes. If I'm not able to play this year, I'll go into next year and try to build off that."

Wallace doesn't mind facing left-handers

PITTSBURGH -- Rookie first baseman Brett Wallace had more success against left-handers than right-handers in the Minor Leagues, and he has carried over that trend to the Major Leagues, even though he's often out of the lineup when the Astros face a left-handed starter.

Wallace entered Friday hitting .250 against left-handers in only 24 at-bats, but was batting .198 (20-for-101) against right-handers.

"Growing up, you never sit against them in high school and college and even in the Minor Leagues, so I'm pretty comfortable against them," Wallace said. "Since I've been here, I haven't faced all of them, so when I get my opportunity I try to stay locked in and focused and dive the ball through the middle."

Wallace hit .301 this season at Triple-A Las Vegas before being acquired by the Astros from the Blue Jays in a secondary trade after the Roy Oswalt deal with the Phillies. He batted .384 against left-handers and .267 against right-handers.

"The biggest thing for me is the more lefties or righties or knuckleballers you see or whatever, you're going to be more comfortable," he said.

Castro's effort has impressed Mills

PITTSBURGH -- Astros manager Brad Mills has been pleased with how catcher Jason Castro has prepared himself for each of his starts, poring over scouting reports and video with pitching coach Brad Arnsberg. Castro has caught 62 games, which are the most by an Astros rookie since Mitch Meluskey in 2000.

"He's done a real good job," Mills said. "We've talked about his aptitude for the game and his willingness and desire to learn. When he got to the big leagues [in June], he had to learn a full pitching staff, and that was amazing. Offensively, it's going to be a continuing learning process for him."

Castro, the club's first-round Draft pick in 2008 out of Stanford, has struggled at the plate this year. He entered Friday hitting .204 with two homers and seven RBIs in 181 at-bats. He hit .265 in 211 at-bats at Triple-A Round Rock this year.

"Offensively, it's going to be a learning process and continues to be a learning process for a long time," Mills said. "You try to give [rookies] as many at-bats as you can to give them the opportunity to see where they are, how much of a learning process it's going to take, until they become the kind of hitter they're capable of becoming."