The right-hander filled the role in the best-of-five AL Division Series against Oakland and the best-of-seven AL Championship Series against the Yankees. He'll do the same against the Giants.
Scherzer has allowed one earned run and struck out 18 over 11 innings this postseason. It's the type of pitching most teams would want to get as often as possible in a seven-game series. The Tigers are concerned about the flipside, not getting it at all. With three other starters pitching as well as they have all season, it's a luxury the club can afford to take.
"Some people have asked about, 'Should he pitch in the fourth game?'" manager Jim Leyland said on Tuesday. "But because of his little bit of setbacks recently, not too recently, but with the celebration and prior to that with a little tired arm, we decided this was the best way to go."
It all goes back to the right shoulder. No matter what the results for Scherzer, and they've been increasingly positive since his return at the end of the regular season, the Tigers aren't going to take a chance.
On one hand, team officials downplay the injury. When right shoulder soreness scratched Scherzer from one start after two innings and erased his assignment from another with a week to go in the regular season, he was diagnosed with deltoid soreness, not tendinitis.
"I know everybody keeps talking about that [as a shoulder injury], but it was definitely muscular," team president/general manager Dave Dombrowski said last week. "They identified it quickly, so it was really more a matter of making sure he got it where it was rested again.
"Like [doctors] said, it's just like a person that's tired. But I was concerned, as far as getting it up and going again."
Even so, shoulder fatigue is enough for the Tigers to use caution. It's not the injury itself, but the chance that trying to push too hard to pitch through it could lead to something else.