MLB

JASON ISN’T FIRST OPTION AT FIRST BASE

Jason Giambi will need to pack his first baseman’s mitt for the playoffs – just in case – but probably shouldn’t expect to use it much, if any.

As tempting as it could be for Joe Torre to add Giambi’s big bat to the lineup at first base, the Yankees manager said yesterday that Doug Mientkiewicz is the preferred choice, with rookie Shelley Duncan in consideration to start Game 1 of the AL Division Series tomorrow against Indians lefty C.C. Sabathia.

With Chien-Ming Wang and his sinker taking center stage for the Yankees, Torre’s decision will likely come down to whether he values getting a better glove (Mientkiewicz) in the starting lineup or a right-handed bat (Duncan) to counter Sabathia. As for the defensively challenged Giambi, he’ll compete for at-bats at DH throughout the series.

“Jason is considered more of a DH who could play first base,” Torre said. “Right now, I’m leaning toward Doug, and we played Dunc there the other day, I just wanted to see what options we have. Jason coming off the bench or DHing is probably what his role is going to be.”

A month ago the idea of Mientkiewicz entering the playoffs as the Yankees’ first baseman would have seemed ludicrous. But after returning from a nearly three-month stint on the disabled list and hitting .429 with a homer and eight RBIs in September, Mientkiewicz has opened more than a few eyes.

“I feel that I’ve done everything I can to show [Torre] when he puts me in there to expect good things, and now it’s out of my hands,” Mientkiewicz said. “Do I want to play? Of course I do. That’s why I signed here.”

But Mientkiewicz also knows he probably wouldn’t have received this opportunity had Andy Phillips remained healthy. Phillips, who had emerged as the regular first baseman, broke his right wrist when hit by a pitch in August, opening the door for Mientkiewicz’s return.

“I know how I got my opportunity, and that’s why I’m not real giddy and doing back flips, because it’s unfair,” Mientkiewicz said. “But I also knew that someone had to pick up the slack when [Phillips] left.”

Giambi will find himself in a DH mix that includes Hideki Matsui, who is bothered by a sore right knee. Duncan would also be a DH candidate.

Giambi said it didn’t seem strange to enter a postseason not knowing his role.

“We have a lot of great players,” Giambi said.

But he also hinted he deserves to play. Giambi missed two months in the middle of the season with a left foot injury.

“I just kept battling, and at the end of the season I felt I swung the bat well and took some good at-bats,” Giambi said. “But whatever is best for the team.”

mpuma@nypost.com