MLB

Tex a Mark-ed man in October

THERE is no doubting the impact Mark Teixeira has had on these Yankees, no denying the way his bat has bolstered a lineup already bursting with power, no diminishing how many runs he has saved with his glove at first base.

Until Joe Mauer did everything but bludgeon would-be voters over the head with his off-the-charts numbers, it was Teixeira who had emerged as the presumptive favorite to win the American League MVP. It was Teixeira who best adapted not only to Yankee Stadium’s agreeable dimensions but also to its inviting gaps. It was Teixeira who inspired not one but two John Sterling catch phrases.

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“He’s had about as good a first year in New York as anyone could ask for,” said Derek Jeter, who knows a thing or three about making positive first impressions. “I don’t know what else anyone could have asked for.”

That’s not true, of course. Jeter, as much as anyone, knows the answer to that question. Because it will be Teixeira who will draw as much attention, as many eyes, as anyone when the Yankees begin their quest for a 27th title tonight at Yankee Stadium in Game 1 of the ALDS against the Twins.

Teixeira pounded 39 homers and collected 122 RBIs and piled up an OPS of .948, and he did all of that out of the No. 3 slot in the batting order, and it seemed that whenever the Yankees needed a big hit across the season’s final five months it was Teixeira ambling up to home plate, an expectant buzz trailing him there from the on-deck circle.

And he is no October virgin. He was, in fact, one of the few Angels who didn’t dissolve like shrinky-dinks last year against Boston, getting seven hits and four walks in 20 plate appearances, the one man standing between the Angels and a broom. It was his first taste of the postseason and he took to it like he was easing into slippers and a smoking jacket.

Still . . . that was Southern California.

This is the South Bronx. And as magnificent as he has been through most of the season, there is still an unfinished portion of Teixiera’s New York resume. The hazing isn’t over. In many ways, it only begins tonight.

“Every game in New York is exciting,” he said yesterday, after the Yankees worked out in preparation of an opponent they didn’t learn until nearly 10 last night. “The whole year I was amazed at the crowds who would come out every day. They expect big things from us. And we expect the same.”

It was a different Teixeira who chatted yesterday than the one who stood stoically at his locker on the evening of May 7. The Yankees had just lost to Tampa, 8-6, and their record stood at 13-15. Teixeira had gone 0-for-5 with a strikeout, his batting average had dipped to .198 and he had begun hearing ever louder waves of boos at the Stadium.

“Nobody’s happy with the way things have gone so far,” Teixeira whispered that night. “Least of all me.”

That is the line of demarcation for this Yankees season. Starting the next night, Alex Rodriguez returned and the Yankees went 89-44 the rest of the way. Starting the next night, Mark Teixeira would hit .310 with 34 homers and 107 RBIs. So as much as Rodriguez brought himself back to Baltimore that night, he also helped drag Teixeira into the season, too.

And if there is one nagging concern about Teixeira, there it is. During the 18 games when the Yankees needed him to perform like a $180 million player, he was essentially a .180 player. When he signed, he made little pretense about liking the Yankees because he would have other big-ticket players around him, and the truth is, this season, he performed when nestled amid that high-priced and talented cocoon.

Sometime in the next few weeks, the Yankees are going to need more from Teixeira. They may even need him to carry them for a few games, the first games since May 7 when that will be a strict part of his job description. And the Yankees’ fate may well come down to how he answers the simplest of all questions:

Can he?

michael.vaccaro@nypost.com