MLB

Without Pettitte, Hughes’ quota could limit Yankees

The Yankees have 43 games to go, but, despite formidable competition from the Rays and Red Sox, GM Brian Cashman doesn’t believe his team should require all of them to clinch a playoff spot.

Cashman was talking with The Post about Phil Hughes’ innings limit when he reminded us that the boundary stops when the postseason starts.

“That’s a situation where it’s live or die,” the GM said before CC Sabathia beat the Tigers, 6-2. “It wouldn’t be fair to the other 24 guys fighting for a championship not to allow him to pitch then.

“There are no restrictions in the postseason. It’s a different animal. We all have a common goal. It’s all hands on deck.”

We then asked Cashman why the same case couldn’t be made for, say, the final two weeks of the season when the Yankees play 10 of their final 13 against Tampa Bay and Boston, and might need to win more than their fair share just to make the playoffs.

“We have 162 games to get the job done and if we need the final week, then we haven’t lived up to our maximum potential,” Cashman said. “And in that case, it wouldn’t be right to put it on this kid’s shoulders.”

So making the playoffs isn’t what’s expected, making the playoffs with a week to spare is now the mandate? Odd, but when Bucky Dent hit that home run in Fenway, nobody seemed to mind that the 1978 Yankees needed 163 games to clinch a post-season berth.

The innings-limit is going to become a September issue for the Yankees, who remain tied with Tampa Bay for the division lead while holding a 5 1/2-game lead over Boston in this three-into-one-won’t-go race.

The prospect of the limit limiting the Yankees became that much more likely when an MRI following a pregame bullpen session revealed a small persistent strain of Andy Pettitte’s left groin, the injury that has sidelined the invaluable lefty since July 18.

The Yankees had been projecting an early-September return for Pettitte, 11-2 with a 2.88 ERA. Now, it’s unlikely that Pettitte would be able to rejoin the fray until the middle of the month. Beyond that, it’s questionable as to how effective he can be after having thrown just 2 1/3 innings since the all-star break.

“It certainly hurts,” Cashman said after the game. “You can’t replace Andy Pettitte.”

If the Yankees can’t replace Pettitte, they’re not likely to be successful attempting to patchwork through September if manager Joe Girardi is obligated to pick his spots with Hughes, 14-5 with a 3.94 ERA and currently No. 2 in the rotation behind Sabathia.

Hughes, scheduled to start tomorrow, has thrown 1342/3 innings, leaving approximately 35 until he reaches the cap. With next Thursday the only scheduled off day through Sept. 8, there’s little opportunity to skip him over this run during which Hughes would start four times.

“We’ll probably just go [on rotation],” Girardi said when asked for the short-range plan.

That means Hughes could bump perilously close to his limit with more than three weeks to go. Then what, 23-year-old Ivan Nova promoted from Triple-A Scranton/Wilkes-Barre to pitch against the Rays and Red Sox the final two weeks?

Or maybe Girardi will choose to pull Hughes a couple of times after the fifth inning regardless of how well he’s pitching. Experience suggests this is risky business even if the bullpen is very deep and has been very good.

“Joe and the coaches know the limit, but it’s their responsibility to manage it, not mine,” said Cashman. “I give them the number and it’s up to them to decide how to get there.

“It’s not in our best interests to publicize what that number is, but we won’t exceed that number, I can tell you that.”

It’s not in the Yankees’ best interests to go without Pettitte. It’s not in the Yankees’ best interests to go down to the final week, either.

The GM told us that, too.

larry.brooks@nypost.com