He proved it in his final three starts of the regular season, going 2-0 while allowing four runs and 13 hits in 24 innings.
Showalter has selected Jason Hammel (8-6, 3.43) to start on the mound for the Orioles, even though the right-hander has pitched only twice since July 17 and not since Sept. 11. Hammel had surgery on his right knee in July and returned to pitch in two games before experiencing pain in the same knee.
"No concern with the knee," Hammel said. "First and foremost, I want to thank Buck for having the confidence in putting me back out there in such an important situation."
Hammel was 8-2 with a 2.61 ERA on June 22. He lost his next four starts, in part because the knee was becoming a problem, and he went on the disabled list after making an early exit from a game in Detroit on July 13.
He pitched a simulated game Monday and a bullpen session Friday, and said both sessions went well.
" He's not so far removed. It's not a pitch count thing or anything," Showalter said. "The challenge is going to be the Yankees, and they'll let us know how he's pitching. We're excited about the possibility of getting him back."
The Yankees will have Pettitte follow Sabathia in Game 2, with Hiroki Kuroda starting Game 3 at Yankee Stadium and Phil Hughes pitching Game 4.
Girardi weighed pitching two lefties in a row against giving Kuroda more days off and getting Pettitte on the mound sooner — he last pitched Sept. 29.
"We just felt that the extra rest would probably help him," Girardi said of Kuroda. "We don't want Andy to go too long without throwing, so it's kind of those two factors."
Showalter is leaning toward rookies Wei-Yin Chen in Game 2 and Miguel Gonzalez in Game 3 depending on the weather Sunday. If there's a rainout things could change, he said.
New York comes in as the favorite, but that means nothing to the Orioles. Getting a fine start from August addition Joe Saunders, Baltimore knocked off the two-time defending AL champs on Friday night in Texas.
"The Rangers were the consensus favorite to win the American League, and for us to come out of nowhere was pretty awesome," reliever Darren O'Day said. "We were picked to finish in the basement in the AL East. The only guys who believed in us were the guys in our clubhouse. We just kept playing."
And so, the Orioles will keep playing well into October.
"People thought we'd be making tee times right now," O'Day said.
NOTES: Yankees OF-DH Andruw Jones says he will not be on the roster for the division series. ... Showalter says INF Wilson Betemit (right wrist) took batting practice and felt good, and that he could be a factor when finalizing the roster.