With left-hander CC Sabathia set to come back for Monday's Game 3, Burnett will move from the bullpen back to the rotation. Burnett was 11-11 with a 5.15 ERA in 33 appearances (32 starts) this year.
"His month of September was not bad," Girardi said. "You look at the strikeouts per nine innings, it was a complete turnaround from August."
Burnett struck out 36 batters in 29 1/3 September innings over six games (five starts), going 2-0 with a 4.30 ERA in the month. He was 1-2 with a 11.91 ERA in five August starts, striking out 17 in 22 2/3 innings.
In six career playoff starts, the 34-year-old Burnett is 1-2 with a 5.67 ERA. The Yankees originally planned on using him as a reliever for this round, but will need four starters due to Game 1's suspension on Friday.
"I have all the confidence in the world in A.J.," Yankees catcher Russell Martin said. "He's had some good postseasons, so I think, in his mind, he's ready to go."
Burnett did not appear in last year's ALDS against the Twins, but took a loss in Game 4 of the AL Championship Series against the Rangers, serving up a key sixth-inning, three-run homer to catcher Bengie Molina in a 10-3 defeat.