The Astros (75-67) shut out their opponent for the fourth time in six games Saturday, beating the Rockies (67-76) 2-0. Houston won for the ninth time in its last 10 games, and its pitching staff has a 2.08 ERA in that stretch.

Roy Oswalt pitched the latest gem for Houston on Saturday with a complete game as he threw 102 pitches and gave up only a leadoff single to Brad Hawpe in the fifth inning. Oswalt struck out six and was backed by Hunter Pence's two-run home run in the sixth inning.

Houston remained seven games behind the Milwaukee Brewers for the wild card, though. Milwaukee won over San Diego on Saturday.

Colorado's loss was only its seventh in the last 20 games. The Rockies are trying to repeat last season's late-season run to the playoffs which ended in a sweep by the Boston Red Sox in the World Series. They are in third place in the NL West, 5 1/2 games behind the first-place Los Angeles Dodgers, who have won seven in a row.

"Time is slipping away, we need to win as much as we can, but there isn't much you can do about this one," Colorado manager Clint Hurdle said Saturday.

Wandy Rodriguez (8-6, 3.76 ERA) looks to continue the Astros' strong pitching as they try to win a series at Coors Field for the first time since 2005.

Rodriguez is 1-0 with an 0.71 ERA in his last two starts. He allowed seven hits in 5 2-3 innings of a 3-0 win over St. Louis last Sunday before leaving with a strained right oblique muscle.

"I felt a pain in my side. ... I was trying to throw (Albert Pujols) inside and I threw too quick," said Rodriguez, who expects to be OK to pitch against the Rockies.

Rodriguez is 3-1 with a 3.60 ERA in six career starts against the Rockies. He lasted four innings against them on April 19 because of a sore left groin, allowing two runs - one earned - and five hits in a 3-2 loss, not factoring in the decision.

Like Rodriguez, Jorge De La Rosa (8-7, 5.23) has also pitched well recently, and takes the mound Sunday looking to win his third straight start. He is 2-1 with a 0.95 ERA in his last three outings. On Monday against the Giants, the left-hander allowed four hits in seven innings while striking out six in a 4-0 win.

"He continues to take steps forward," Hurdle said. "He's got momentum going for him and confidence."

De La Rosa doesn't have any decisions in seven relief appearances against the Astros. He's pitched 6 2-3 innings against them, allowing five runs - four earned.