Instead, the problem was cramping in Garza's right triceps. His next start would be Friday at Wrigley Field, and he was to be re-evaluated on Sunday.
"It started getting a little tight in warmups for the third inning," Garza said. "I figured it would loosen up. I went through that [third] inning and felt all right. The first fastball to [Rafael] Furcal didn't feel normal, but I just kept going and got out of the inning.
"I came down and went straight to the cage and tried to make a couple throws, and it just started cramping. I went straight to [pitching coach Chris Bosio] and said, 'Have you ever had this before? Have you ever dealt with this?' He made the call and said it was not worth the risk."
Garza had thrown three shutout innings against the Cardinals, giving up two hits and walking two. The injury was not related to a wild double play in the Cardinals' third.
He underwent X-rays as a precaution, and they were negative. The right-hander was making his 18th start.
The cramping was not believed to have been caused by dehydration. Garza said he'd been drinking water for two days to prepare for the start. He hasn't felt this kind of discomfort before.
"Anything to do with your elbow area as a pitcher, you get nervous," he said. "I'm still young, and I wanted to take the precautions, so I said something. Usually, I wouldn't say anything, and I'd try to go out there and muscle up."
There were scouts from the Dodgers, Yankees, Angels, Royals and Pirates at Busch Stadium to watch Garza. They must have checked their cellphones to see if someone had made a deal.
"If that's what [people] thought, it's going to take a lot more to pull me out of a game than a trade," Garza said. "They're going to have to wait until I'm done."
He could be dealt by the July 31 non-waiver Trade Deadline but he also could be a key part of what the Cubs are trying to do, general manager Jed Hoyer said.
"We've said that all along," Hoyer said before Saturday's game. "He's a really good pitcher. We need more guys like him in the organization, not fewer. We've been very consistent with that all along. He's a guy who can certainly help the team win, not just this year, but next year and for a long time."
It's a tough decision.
"There's always a case when you're dealing with a young starting pitcher who's a horse, who can dominate a game, who has the stuff and all that [to keep him]," Cubs manager Dale Sveum said. "Those are the million dollar questions that an organization has to deal with. Sometimes it's like gambling when you do trade guys like that. The gamble is the guys you get in return can fill that role, too. You might get one, two, three guys who can be productive Major League players."
Garza, whose wife is expecting the couple's fourth child soon, has a short wish list.
"All I want to do is play ball," he said. "And I didn't get to do that today and I'm just [ticked] off and frustrated."