HOUSTON -- Left-hander Tim Byrdak, who's been on the disabled list since May 4 with a left hamstring strain/lower back disk irritation, rejoined the team on Friday after throwing a scoreless inning in his first of two scheduled rehab stints on Friday at Triple-A Round Rock. He threw 14 pitches.

"He said he felt really good and threw the ball well, and he'll take the mound again tomorrow for another inning," Astros manager Brad Mills said.

Byrdak will return to Round Rock on Sunday to pitch one inning against Reno and should be activated in time for Tuesday's game against the Brewers in Milwaukee, if all goes well. Byrdak, who got a cortisone shot in his lower back a week ago, is 1-0 with a 5.23 ERA in 13 games.

Gustavo Chacin has taken over Byrdak's role as the lefty in the bullpen and has pitched well, posting a 2.08 ERA in three games. Those are his first three career relief appearances after starting 58 games in the Majors to start his career.

Mills not concerned about Oswalt situation

HOUSTON -- Astros manager Brad Mills said he and Roy Oswalt had a discussion on Friday night about the club's admission the ace pitcher had asked to be traded, and Mills is ready to put the situation behind him.

"I was fine with everything," Mills said. "He was in a good frame of mind, I thought. I'm going to leave it at that. I'm really not going to give it a second thought. He's been very open with me and [pitching coach Brad Arnsberg] and [general manager] Ed [Wade], as far as I know. Everything was fine. I thought he handled everything well."

Oswalt's agent informed owner Drayton McLane this week that the right-hander would like to be traded. Oswalt addressed the media prior to Saturday's game and said he would like to be traded to a contender, but reiterated he hasn't demanded a trade.

Mills doesn't think the Oswalt situation will serve as a distraction in the clubhouse.

"It definitely is blown up a lot more outside of the clubhouse than what is going on in the clubhouse," he said.

Lineup at its best when pitching's sharp

HOUSTON -- The Astros won their first game of the season on Friday when scoring two or fewer runs, beating the Rays, 2-1, in the series opener. Houston was 2-for-12 with runners in scoring position, but slugger Lance Berkman said the team's woeful offense looks a lot better when the pitching is as sharp as it was Friday.

"I hate to put it all on the starting rotation, but that's what got us to the World Series [in 2005]," Berkman said. "We had a superb pitching staff from top to bottom. Our rotation was outstanding, the bullpen was solid and we did just enough offensively, just like [Friday] night.

"The difference between a horrendous offense and a scrappy offense is your pitching staff. You win, 2-1, and it's, 'You broke up a double play' and 'You got a big hit from Hunter [Pence],' and that's why you won, 2-1. If you lose, 3-2, you didn't muster anything."

But Berkman admitted the offense needs to do its part, too.

"The reality is, we have not been a very good offensive team," he said. "That's stating the obvious. I think we are the worst offensive team in baseball to this point in the season. We need to improve on that, and if we can do that and continue to get solid work out of the rotation, that will fuel a run that will get us back to where I think we should be from a talent standpoint."

Worth noting

The Astros made a lineup change just minutes before Saturday's game, starting Geoff Blum instead of Pedro Feliz. It was not injury-related. ... With a scheduled off-day Monday, Astros manager Brad Mills said some regulars could be out of the starting lineup in Sunday's series finale against the Rays. ... Lance Berkman began Saturday needing three walks to reach 1,000 for his career.