Yankees manager Joe Girardi wants to throw as many lefties as he can against a Minnesota lineup that is loaded with dangerous lefties, so he will bring Sabathia back for Game 4 on short rest if needed, while Pettitte, who would pitch on regular rest because of the off days in the schedule, would start Game 5 if necessary.
"We felt with all the left-handed hitters we would try to throw four lefties at them in five games," Girardi said.
Burnett's place in the playoff rotation has been speculated about in the local and national media for several weeks. He is on the postseason roster, however.
Girardi is expected to hold a news conference on Tuesday afternoon in Minnesota.
The move to leave out Burnett for the ALDS is not shocking, because Girardi mulled removing Burnett from the rotation during the second half of the season. General manager Brian Cashman has said the Yankees' postseason rotation would be based on merit, not money.
Burnett is completing the second season of an $82.5 million, five-year contract, but has not come close to living up to his salary this season, in which he was 10-15 with a 5.26 ERA. He took the news in stride.
"It'd be different if I had a great second half," Burnett said. "But I took baby steps, not a huge leap. Those three guys [Sabathia, Pettitte and Hughes] have been our main starters."
In October 2009, with the Yankees down a game in the World Series, Burnett won Game 2. Overall, he was inconsistent in the 2009 playoffs.
"We really like the way [Mitre's] sinker has been working lately and the way he has been throwing the ball," Girardi said.
Girardi left open the possibility that Burnett could start in the series if Sabathia told the Yankees that he didn't feel good enough physically to pitch on three days' rest. But if all goes according to plan, Burnett will remain in the bullpen.
"I'm not going to cause drama or be the bad apple," Burnett said.
Girardi said all his roster decisions were difficult and he appreciated how Burnett handled the news.
"I didn't know how he would take it," Girardi said. "But we talked about it and he seemed like he's on board. He's going to do whatever he can to help us."
Wallace Matthews covers the Yankees for ESPNNewYork.com. Andrew Marchand is a senior writer for ESPNNewYork.com. Information from The Associated Press was used in this report.