"Yeah, we'd like to have Soriano, but we don't so you flip the page and move on," reliever Michael Wuertz said. "You can't worry about it. We've got 25 guys and we have to go out there and do our job."
Chicago, which remained one game behind NL Central-leading Milwaukee, threatened in the 10th against Brad Lidge (3-1) when Jason Kendall singled leading off, took second on a sacrifice and advanced on a flyout. Lidge then struck out Cliff Floyd.
"A leadoff walk kills you every time - it's that simple," Wuertz said. "You walk that guy, it comes back to haunt you."
After Eric Bruntlett flied out, Wuertz threw a wild pitch and Munson singled to right. Chicago dropped to 1-7 in extra-inning games this season.
"It's tough to lose a game that way," Wuertz said. "I threw him a slider and he hit it. I threw the same pitch at 3-1. It just ended up being too fine. That's what happens when you fall behind in the count as well."
Ryan Theriot doubled twice for the Cubs, who have lost four of five.
Chicago manager Lou Piniella said before the game that a scan revealed Soriano had torn his right quadriceps while running the bases against the New York Mets on Sunday night at Wrigley Field.
"We think he'll be out four-to-six weeks," Piniella said. "We think it will be around Labor Day."
Wandy Rodriguez struck out a career-high nine for the Astros, who had lost six of their previous nine. Rodriguez gave up one run and four hits in eight innings, and his 121 pitches were a season high for the Astros. Chad Qualls and Lidge completed the five-hitter.
Rodriguez is 6-2 at home with a 1.69 ERA -- second-best at home in the majors. On the road, he's 1-8 with an NL-worst 8.16 ERA.
"I feel the same on the road," he said. "I feel comfortable at home but I feel just as comfortable on the road."
Manager Phil Garner also can't explain it.
"I've seen it before but I don't know why it happens," Garner said.
Cubs starter Rich Hill allowed one run and three hits in seven innings. He has four no decisions since beating San Francisco on July 16.
"We got a good game out of Hill, and we squandered some scoring opportunities," Piniella said. "You hold a team to two runs in 10 innings, you should win."
Carlos Lee put Houston ahead in the fourth with his 24th homer, an opposite-field drive to right. Theriot doubled leading off the fifth and scored on Derrek Lee's grounder.
Rodriguez worked his way out of a bases-loaded jam in the fourth when he got Hill on a called third strike. After the Cubs scored in the fifth he retired 12 straight, striking out the side in the eighth. Qualls struck out the side in the ninth.
After this three-game series, the Cubs go to Colorado for four games before returning home. It could be a key stretch.
"The next six days," Wuertz said, "we've got to play really well."
- Chicago's Eric Patterson made his major league debut, playing left field in the ninth and sacrificing in the 10th. He is the brother of Corey Patterson, who played for Chicago from 2000-05. The Pattersons became the 10th set of brothers to play for the Cubs.
- Houston has homered in a season-high nine straight games.