Zimmermann pitched three innings and allowed eight runs on nine hits. He threw 61 pitches, 39 for strikes. St. Louis went to work on Zimmermann in the second, scoring two runs. David Freese scored on a groundout by Rob Johnson, while Shane Robinson scored on a single by Ronny Cedeno to make it 2-0.
The Cardinals sent 10 hitters to the plate in the third and scored six runs off Zimmermann. Johnson and Greg Garcia highlighted the scoring with two-run hits.
Zimmermann didn't give any excuses for his disappointing outing. He never talked about having a dead arm and said he felt fine. He did acknowledge, however, that he felt tired in the third.
"I just threw some fastballs up in the zone," Zimmermann said. "Obviously, they are a good hitting team. When I did make some good pitches today, they put some good wood on it and hit a few down the line."
Zimmermann is part of a formidable rotation that includes Stephen Strasburg, Gio Gonzalez, Dan Haren and Ross Detwiler. The rotation is expected to help the Nationals attempt to win their second straight National League East title.
Last year was Zimmermann's best as he went 12-8 with a 2.94 ERA in 32 starts. He wants to improve upon that and pitch at least 200 innings. He was 4 1/3 innings off the mark last year.
"I have to go deep in the ballgame," Zimmermann said. "I think last year, I averaged about six innings a game, so if I can average seven innings, you could get it easily. Thirty starts and seven innings is 210 innings. If I could average seven innings, I should be able to make it."
He is developing a changeup that he feels comfortable throwing at any count. He used the pitch four times against the Cardinals.
"I finally got to the point where I feel comfortable throwing the changeup at any time," Zimmermann said. "I'm able to control it, keep it down in the zone. The velocity is good. I think it's going to be a big pitch for me."
Zimmermann is also showing how successful he could be after having Tommy John surgery in August 2009. By last year, he was third on the team in wins.
"It's a tough process when you first find out about [the surgery], but the success rate is so good, most guys come back to their normal selves or even a little better," Zimmermann said. "When I first had it, I told myself I was going to come back in 12 months. I put in all the work I possibly could to get better every day and build the arm strength up. It feels good every day."
Asked if he is a better pitcher today after having the surgery, Zimmermann said, "I think I've learned a lot more. My arm is about the same. I learned how to pitch more. I was more of a thrower before Tommy John surgery. I'm learning what pitch to throw in what count. I'm setting guys up and I wasn't doing that before."