NEW YORK -- With Mariano Rivera's saves record in the past and their division rivals fighting for second place among themselves, it's about time to think about the Yankees and the playoffs, which brings us to a question nobody seems capable of answering.

Who will start for them?

"I definitely wouldn't want to be the one having to make that decision," one candidate, Phil Hughes, said. "All I can do is go out there and pitch and not worry about it."

But it is something to worry about. Because while the Yankees' rotation has been good enough to get them the first-place record they now hold, and good enough for general manager Brian Cashman to stand pat, what they have, with little more than a week before the postseason, is CC Sabathia and five question marks.

One -- Ivan Nova -- is inexperienced.

One -- A.J. Burnett -- is an enigma.

One -- Hughes -- hasn't been the same this season.

And two -- Freddy Garcia and Bartolo Colon -- are veterans who seem to be slowing down at the wrong time.

Sure, almost every team has issues this time of year. The Braves and Red Sox have suffered a rash of injuries, and even the world-beating Phillies are leaking oil down the stretch, but nothing is more fascinating than the five guys who fall behind CC in the Yankees' staff.

FOR STARTERS ...
ERAs of starters vying for a place in the Yankees' postseason starting rotation (innings pitched in parentheses):
PITCHER BOS DET LAA TB TEX
Burnett 7.36 (11) 3.75 (12) 6.00 (6) 6.48 (16.2) DNP
Colon 3.00 (15) 5.73 (11) 2.45 (18.1) 4.50 (12) 10.38 (4.1)
Garcia 6.92 (13) 5.14 (7) 9.00 (5) 0.00 (6.2) 0.00 (6)
Hughes 14.63 (8) 11.25 (4) DNP 3.00 (6) DNP
Nova 8.31 (4.1) DNP 3.75 (12) 1.69 (5.1) 4.67 (17.1)

Right now, any one of them could be the No. 2 man in the playoffs, and any one of them could be relegated to bullpen work.

"A lot of it will probably, if we're fortunate enough to get in, be determined by the matchup," manager Joe Girardi said. "Until we get there or see how guys are doing, we've always said things have sometimes a way of working their way out. So, we'll see."

Girardi has many questions to ponder.

Does he go with a three-man staff, which made his club World Series champs in 2009 with Sabathia, Burnett and Andy Pettitte starting all their playoff games? Does he go with the battle-tested veterans who have been there before, meaning Garcia and Colon get the nods? Does he take out the veterans, since they've racked up a bunch of innings and it's actually Hughes and the superb Nova who have been pitching better?

And what in the world does he do with Burnett?

With the Yankees' magic number to clinch a playoff spot at four, and five to clinch the American League East title, it's almost time for Girardi to make some really tough choices.

But apparently it still isn't time to talk about them.

"I'm not worried about the postseason right now," the Yankees' skipper said Monday. "Right now, I'm worried about winning games. I'm not going to worry about the rotation -- I've been asked for probably the last two months. We have to get in. I'm worried about this week, not what's going to happen maybe in the future."

He may say that, but there's no doubt Girardi is sifting through what to do if and when the Yankees are officially in the playoffs. He's too meticulous and the subject matter is too important for him not to.

With that in mind, here's a look at those other five starters, starting with the biggest riddle ...

Burnett (10-11, 5.28 ERA): He represents perhaps the most difficult, delicate question of all. Burnett -- making $16.5 million annually through 2013 -- has a 5.28 ERA in 31 starts and a combined 5.27 ERA over the past two seasons. There are so many times when he'll make you believe there's no way he'll ever be a productive pitcher again, but then there are those few moments -- maybe it was the 11 strikeouts against the Mariners, or the two runs he gave up to the Red Sox on Sept. 1 -- when you think maybe, just maybe, he can have an impact on the postseason once again.

One thing seems certain: Cast him aside now and you may lose him forever.

Colon (8-9, 3.81 ERA): He's been easily the most pleasant surprise on the Yankees' staff, but he's thrown 156 innings, which is plenty more than the combined total he had from 2008-10. In fact, he hasn't topped 100 innings since 2005. Considering that, Colon's six-run, four-inning outing against the Blue Jays last weekend has to be a red flag -- even if it came after seven shutout innings against the Angels.

Garcia (11-8, 3.77 ERA): Garcia has been incredibly steady all season -- until recently. The 34-year-old has a 10.95 ERA while failing to pitch into the sixth inning in each of his past three starts. He went 10 straight outings without allowing a home run, and now he has given up seven in his past four starts. Garcia will say that part of the reason may be that his schedule is out of whack since he's not used to pitching after long layoffs and Girardi has been going with a six-man rotation, but who really knows if that's the case?

Something to consider, perhaps: Garcia is 6-2 with a 3.11 ERA in nine career postseason starts.

Hughes (5-5, 6.00 ERA): Hughes was so big for the Yankees in his first full season as a starter last year, but can the 2011 Hughes be trusted when games matter most? Maybe the recent Hughes can be. Despite his ugly-looking numbers, the 25-year-old has given up just three runs in 12 innings over his past two starts. But in two starts prior, he gave up 12 runs in 8 1/3 innings. Inconsistencies may hurt his chances of making the playoff rotation again, and so may the fact he's proven to be effective out of the bullpen, as he was in 2009.

Nova (15-4, 3.81 ERA): It's numbers like those that make you think we may be looking at the Yankees' second-best starter right here. Nova has been solid all year and great lately, going 7-0 with a 3.32 ERA in his past nine starts. But he's 24, is in his first full season in the big leagues and has never sniffed the playoffs -- unless you count the Minor Leagues.

Can he really be the Yankees' No. 2 man?

"I want to be there," Nova said. "... My first time being in a playoff rotation, and with a team that I like, it's part of my dream that's coming out, in a way. I want to win a championship, too, and it's going to be an unbelievable feeling for me and my family, friends, so I hope I can be there."