Pittsburgh, which is batting .218 and has an 8.02 ERA during its 11-game road skid, gives the ball to Charlie Morton (3-7, 5.43 ERA), whose last start was pushed back to give his sore groin more time to heal.
In his last outing on Sept. 1, Morton allowed six runs and nine hits in five innings to take the loss in an 11-5 defeat at Cincinnati.
The right-hander is 0-1 with a 9.90 ERA in two starts against the Astros after allowing five runs in four innings of a 5-0 loss at Houston on July 8.
The Astros turn to rookie Bud Norris (4-3, 6.05) as he tries to build off his first win in a month.
Norris snapped a personal three-game losing streak by allowing two runs in six innings of a 4-3 victory over Philadelphia on Sunday.
Third baseman Jeff Keppinger, who has been out of the lineup since exiting with back stiffness Sept. 4, was scratched from the lineup Thursday after feeling discomfort while attempting to run.
"Talking to (trainer) Nate (Lucero), it's probably better to take another day," Keppinger said.
Keppinger is surprised the injury has forced him to miss so much time.
"I thought maybe it would be two days, but we have a lot of guys here now," he said, referring to the expanded roster. "So instead of trying to push it and get out there, it's better to take an extra day to make sure it's right so it doesn't happen again."
Keppinger took grounders Wednesday and was available to pinch-hit Thursday, but he hadn't attempted to run until minutes before he was scratched.
"Running was the main thing that was bothering me in the game that I came out of when I hurt it," he said. "It was mostly the pounding that sent little jolts in my back. To try to go out there and run, I still felt it. So talking to Nate, the best thing he said to do was to take an extra day. It keeps getting better and better every day, so one more day is probably the best thing for it."
Added manager Cecil Cooper: "He's not ready to go yet. He swung the bat (Wednesday) and felt fine swinging the bat. You have to run the bases. Still maybe not as good as he would like to be on the defensive side, so we're going to give him another day to see what happens. ... Whenever he's ready to go, we're going to get him back in there."
BRAVES 9, ASTROS 7: The Astros lost because Roy Oswalt lasted only two innings, giving up six hits. Down 6-1 after two, they never recovered. It also didn't help that Miguel Tejada hit into three double plays.
3B Chris Johnson got his first start after Jeff Keppinger was scratched from the lineup Thursday. "It is exciting," said Johnson, who made his big-league debut the previous night as a reserve. "I just wanted to get out there and start playing again and get all these nerves out of the way."
LHP Wandy Rodriguez, a day after declining the ball for the eighth inning, says that he doesn't expect to miss his next turn in the rotation.
"I'm fine," he said. "I don't have any pain. I just didn't feel much strength on my pitches (after the seventh inning Wednesday). I'm fine. I'm cool. I'm a bit tired, but it's nothing out of the ordinary. The important thing is that I'm fine and I'll make my next start."
By The Numbers: 52—Stolen bases for CF Michael Bourn, the most in the National League through Sept. 8. Bourn is the first Astro to exceed 50 in a season since Eric Yelding had 64 in 1990.
Quote To Note: "It's the way we were capable of playing all year." —LF Carlos Lee, on the Astros' current three-game winning streak after they were all but eliminated from contention. The Astros finished their game 14 games out in the National League Central race and 10 out in the wild card.
3B Geoff Blum was out of the starting lineup a day after suffering a left shin contusion and mild ankle sprain barreling into second base. "He'll probably not even be ready (Friday)," manager Cecil Cooper said.
1B Lance Berkman, one game shy of tying the longest homerless drought of his career, drilled a three-run home run to left-center field to cut the Braves' lead to 6-4. Berkman had gone 32 games between home runs, one shy of the 33-game homerless streak he had last year. He even had to wait a few extra minutes because Atlanta manager Bobby Cox asked the umpiring crew to review and make sure his home run was good.
Berkman's home run was the 307th of his career, moving him past Ruben Sierra for sixth on the all-time homer list among switch hitters.
SS Miguel Tejada who had been the hero the previous night with a walk-off two-run single up the middle, couldn't duplicate the magic Thursday. He hit into a game-ending double play, his third double-play grounder of the night.
"Can't do it every day," Tejada said. "That's why we're nine guys."
3B Geoff Blum (bruised left shin, mild left ankle sprain) left the Sept. 9 game, and he didn't play Sept. 10. He is doubtful for the Sept. 11 game.
3B Jeff Keppinger (sore right hip) left the Sept. 4 game, and he did not play Sept. 5-10. He is day-to-day.
RHP Roy Oswalt (sore back) left his Sept. 5 start. He made his Sept. 10 start.
RHP Alberto Arias (strained right hamstring) went on the 15-day disabled list Aug. 28. He played catch Sept. 1.
LHP Mike Hampton (left shoulder strain) went on the 15-day disabled list retroactive to Aug. 14, and he was transferred to the 60-day DL on Sept. 7. He was scheduled to undergo season-ending surgeries on his left shoulder and both knees.