Rodriguez struggled for the third successive outing, giving up 10 hits and seven earned runs while striking out seven. He's 0-3 with a 7.90 ERA in his past three starts after going 5-2 with a 1.83 ERA in his first nine starts.
"I had a bad night," Rodriguez said. "I don't know what's going on with me. I think the hitter can see whatever I throw. I don't know how, because tonight I threw a good breaking ball and my fastball had good location and they hit that very well."
The good news was hard to find for Houston.
Edwin Maysonet (2-for-4) had his fifth multihit game of the year, and Michael Bourn went 2-for-5 with an RBI. Slugger Lance Berkman walloped his 336th career double, moving him past Jose Cruz and into sole possession of fourth place on the club's all-time doubles list.
But the Astros, who squandered a chance for their first four-game sweep of the season, were held to four hits and two runs in seven innings by Rockies starter Jason Hammel. The heart of the Astros' order -- Miguel Tejada, Hunter Pence, Carlos Lee and Berkman -- went a combined 2-for-16, with Tejada going 0-for-5 to snap his 17-game hitting streak.
"Even though he had a big lead, [Hammel] was still pitching like it was a one-run lead," said third baseman Geoff Blum, who went 0-for-3 and snapped his six-game hitting streak. "He made pitches when he had to and we didn't take advantage of opportunities."
Rodriguez's troubles began in the third inning, when Ryan Spilborghs led off with a double and scored on a Clint Barmes' triple. Todd Helton's RBI single made it 2-0, and Garrett Atkins socked a two-run homer to left two outs later to put Colorado ahead, 4-0.
"They were hittable pitches," Astros catcher Ivan Rodriguez said. "Basically all those balls were right in the strike zone and good to hit. He cannot do anything about that. He needs to forget it and put it behind him and come tomorrow with a fresh mind, go to the video and work hard and do some work in the bullpen and be ready next time."
The Astros got within 4-1 in the third on an RBI double by Bourn, but it wasn't long before the balls began flying out of the park. Spilborghs homered to right on an 0-2 pitch in the fourth, and Brad Hawpe and Atkins connected for back-to-back homers in the fifth to put the Rockies in control, 7-1.
"To give you an answer as to why it's happening, [it's] probably command and not enough quality pitches and a lot of balls up," Cooper said. "When you do that, we know what happens. Those guys get you. He just has to get back to being who he was before, which is down in the zone and [throwing] strike one with his fastball and using that a lot and using his breaking ball.
"He hasn't had a real good curveball in three or four outings, so needs to get back to that a little bit. I'm sure he's probably shaking a little bit with his confidence. We need to get him back to being who he's supposed to be, pounding the strike zone with his fastball and using his breaking ball."
Ivan Rodriguez said Wandy Rodriguez's struggles are mainly due to command, which was so good earlier in the season.
"He's probably overthrowing a little bit and leaving fastballs up and over the plate," he said. "That's part of the game. He knows that he's probably going to go through that and everybody goes through that. What he needs to do is just work hard and go back and see his videos when he was pitching good, and come back next start and do good."