Andy Petttitte's job description, in some sense, has changed. For so much of this season, the Yankees relied upon Pettitte to bail water out of their sinking ship. Now, with the Yankees as hot as they've been all year -- and the American League East title as real a possibility as ever -- Pettitte has been asked only to further the momentum.

So the context has changed. But little else has.

"We got ourselves backed up in such a hole all year that I've just had to go out and make my starts," Pettitte said. "That's kind of the way I've been approaching it the whole year so far, and that's the way I'll continue to approach it."

The Yankees could use a similar approach on Wednesday, when Pettitte starts in the series finale against the Orioles at Yankee Stadium. Pettitte has won seven of his last eight decisions, the Yankees have won 11 of their last 13 games and there's little reason to believe that either of those trends will change.

The good vibes are flowing, thanks in large part to a September that's boasted everything the Yankees had ached to find over the previous five months.

The pitching has been there, even without Pettitte in top form. He holds a 5.94 ERA in September after a sparkling 2.36 mark in August, but his supporting cast has more than picked up the slack.

And he hasn't needed to be perfect, thanks to an offense that has averaged nearly eight runs a game over the past two weeks.

All of that has conspired to shoot the Yankees 2 1/2 games back of the Red Sox, as close to the AL East lead as they've been since early April. They arrived here only after abandoning any plans to quickly retake the division's top spot, so they'll continue to try to ignore their proximity to the Red Sox for as long as they're able.

"That's based on how you finish, and not where you are now," manager Joe Torre said. "Sure, it's nice to be in the division lead and control your own destiny, and we want to keep it that way. But we want to make sure that we don't get too caught up in what-ifs."

So instead, they'll focus on the facts. They have Pettitte -- their horse -- on the mound, with a chance for a series sweep. And the Orioles are countering with Brian Burres, who, before his gem last week, held a 15.23 ERA over nine previous outings.

All the Yankees need to do is exploit those facts and keep them tilted in their favor. They've done that lately and parlayed it into legitimate postseason expectations. And that, in turn, has changed the very face of this Yankees team.

"I think it's great, no question," Torre said. "You control your own destiny. We have a nice edge to us now."

Pitching matchup
NYY: LHP Andy Pettitte (13-8, 3.89 ERA)
Pettitte wasn't sharp last weekend against the Red Sox, lasting only four innings and needing 101 pitches to do it. The lefty has yet to win in two starts and a relief appearance against Baltimore, despite posting a 3.00 ERA. He's walked nine Orioles in 15 innings, his worst rate against any team by no small margin.

BAL: LHP Brian Burres (6-5, 5.47 ERA)
Burres shined in his return to the Orioles' rotation, tossing seven shutout innings against the Blue Jays. That was his best outing since a seven-strikeout performance against the Yankees on July 28. For his two-year career, Burres holds a 2.53 ERA against the Yankees, with four of his five appearances coming in relief.

Player to watch
Right fielder Nick Markakis has improved upon nearly every facet of his game following a strong rookie season, and he's the only Orioles hitter to crack 20 homers and 100 RBIs this season. Against Pettitte, he has three hits in nine tries.

Tickets
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On the Internet
 MLB.TV
 Gameday Audio
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• YES

On radio
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Up next
• Thursday: Off-day
• Friday: Yankees Blue Jays (Roy Halladay, 15-7, 3.82) at (Chien-Ming Wang, 18-7, 3.82), 7:05 p.m. ET
• Saturday: Yankees Blue Jays (Shaun Marcum, 12-6, 4.15) at (Ian Kennedy, 1-0, 1.89), 1:05 p.m. ET