However, two pitches later, the Cardinals were well on their way to a 9-6 loss to the Brewers at Miller Park.
Ryan Braun, who had knocked a first-pitch, two-run homer in the first inning, swatted Garcia's first pitch to him for a two-run double that cut the Cardinals' lead to 5-4. It took one pitch to Prince Fielder for the lead to go away, the result of which was a two-run homer that chased Garcia from the game.
The moves were open to second-guessing. Should the Cardinals have avoided Fielder? Or should they have avoided the whole situation by replacing Garcia with Octavio Dotel before Braun's at-bat?
But Garcia had cruised through the previous four innings, outside of the Braun homer, and the fact was that he had never given up a home run to Fielder, or even walked him.
The inning started with a Corey Hart ground single into left field on a 2-2 count. It began to spin out of control when Garcia left a 2-2 changeup to Jerry Hairston over the plate and coughed up a double. Two pitches later, the Cards were left playing catch-up.
"Whatever it was, it was fast," La Russa said of how the inning unfolded. "[Garcia] started out the game just getting the ball up, paid for it, and after that the delivery came together and I thought he pitched Hart pretty well, and got a hopper in the hole.
"Then he made three straight pitches right in the middle of the plate, they didn't miss any of them. It just went like that."
La Russa said that up through Hart's hit, on a well-located pitch, Garcia had given him no red flags that suggested any need for advanced early-game strategy.
"The guy is cruising, there's a ground ball [Hart's hit], he makes one mistake [to Hairston]," La Russa said. "How many hits does he have at that point?"
To answer, four. But two pitches later, Garcia's final line read six, but it also has an "L" attached. The Cardinals still need to win four to advance to the World Series, while the Brewers are a step closer.
La Russa had no regrets.
"Only when I saw him throw the ball up the middle to Braun, I said, 'That's enough,'" La Russa said. "And he tried to make a pitch to Fielder, and it's a two-run homer.
"He was throwing the ball better than that. He made one mistake. It's a tough league, but it's not that tough."
Although Garcia had thrown the two bad pitches, the numbers didn't scream that letting him pitch to Fielder was a risk.
Fielder entered with a .286 career batting average against Garcia, but with no home runs, two RBIs, four strikeouts and no walks in 21 at-bats. In 2011, Fielder was 2-for-5 with two RBIs against Garcia.
Even after Fielder turned the numbers, and the game, upside down, Cardinals catcher Yadier Molina didn't second-guess the idea of challenging.
"We've got Jaime," Molina said. "Jaime's gotten him out a bunch. Like I said, we try to get him out. We missed the location."
The Cardinals' strategy didn't surprise Fielder. Seeing a fastball in the middle of the plate delighted him, though.
"Obviously, I think even when they're trying to pitch me, they're not trying to throw it down the middle, they're trying to get me out," Fielder said. "It's fine. I don't really pay attention to it too much, I just try to get a good pitch."
Behind Fielder was Rickie Weeks, who had walked and doubled off Garcia earlier in the game and was 4-for-16 with a home run, four walks and four strikeouts against him in regular-season play.
La Russa knew the pitch to Braun was a warning sign. Still, he saw nothing wrong with giving Garcia a chance to right himself against the dangerous Fielder.
"Once he starts throwing the ball in the middle, there's not much room for margin of error there," La Russa said. "Once he faces Braun, Fielder was going to be his last hitter, and Dotel was ready for the next guy."
After the Braun and Fielder fireworks, Dotel didn't bail out the Cards. Dotel committed a two-base throwing error against Weeks, the first hitter he faced, then served up Yuniesky Betancourt's two-run shot.
Thomas Harding is a reporter for MLB.com. Read his blog, Hardball in the Rockies, and follow him on Twitter @harding_at_mlb. This story was not subject to the approval of Major League Baseball or its clubs.