Johnson ruled out left-hander Gio Gonzalez pitching in relief. Gonzalez will pitch Friday, if a Game 5 is necessary. The Cardinals entered Game 4 up in the series, 2-1.
The last time Zimmermann pitched was Monday in Game 2 in a 12-4 loss. He lasted three innings, allowing five runs on seven hits. He threw 63 pitches, 40 strikes.
"Yes, Jordan Zimmermann didn't throw but 60-something pitches in his last outing, so this will be his throw day and he will be available out of the 'pen," Johnson said prior to Thursday's game.
Said Zimmermann about the Game 4 assignment: "[The club's relievers] were all pretty excited when I told them the news before, so we'll see. Hopefully Det goes seven [innings] and I don't get into this game. It would be the best for everything."
On the offensive side, Johnson decided not to change the lineup even though the team came into Game 4 hiting .240 in the series.
"Well, you know, when you face veteran pitchers, I think young hitters are learning that they don't give in and sometimes you have to make adjustments to center the ball," Johnson said. "Every pitch has a purpose from a veteran pitcher. Every pitch. You go away a couple times to come in. You come in hard to go soft away. Especially with a veteran pitcher, you're not going to get your pitch, so you have to sometimes look in the areas and go the other way, and that's how you hit, period."