MLB

JETER HAS PLAYOFFS ON MIND

The playoffs don’t officially start until Oct. 3, but Derek Jeter says they’ve already begun at Yankee Stadium.

“This is a situation now . . . it’s like we’re in the playoffs,” Jeter said. “We’re playing in the playoffs right now. We need to play well regardless of who we’re playing. We just happen to be playing Boston now. We need to get some wins.”

Last night, they got one. The Yankees knocked off the Red Sox 5-3 in the first game of their three-game series. Jeter helped the cause with a fifth-inning home run, which broke his hitless streak of 14 at-bats and ended a 1-for-18 skid.

Questions began to grow as Jeter struggled and sat out Sunday’s game in Detroit with a right-knee injury. Jeter answered those doubts with one swing. He broke a 2-2 tie with the homer to right off Daisuke Matsuzaka.

Jeter’s ninth homer of the season and first in 87 at-bats came on an 0-1 pitch. It was Jeter’s first hit since Aug. 22 in Anaheim. He never reveals when he is injured and said little about his right knee bothering him.

He hurt it coming out of the batter’s box on Aug. 21 in Anaheim and tried to play through it before taking Sunday off.

Asked if he had to make any adjustments, Jeter seemed annoyed at the question.

“I didn’t adjust anything,” he said.

Jeter, who played Monday, went 5-for-23 (.217) with four runs, one double and one RBI on the Yankees’ road trip.

His home run last night was the 192nd of his career, tying him for 13th all-time on the Yankees’ career list with Tino Martinez, who was at the game.

“We put ourselves in a little bit of a hole,” Jeter said. “If we go out and play well and win our games, like I said before, I like our chances.”

brian.costello@nypost.com