MLB

Mets need to make a big pitch for Mariners’ Lee

It was Colonel Mustard, with the revolver, in the con servatory. Oh, no, so sorry, it was Oliver Perez, with the sore knee, in the trainer’s room.

So much ado over the 25th man on the roster; so much for Perez, who was a Met without a clue this season, only to get one on Friday by reporting a knee issue to manager Jerry Manuel a day before the team was obligated to make a roster move in order to bring Jonathon Niese off the disabled list for yesterday’s start against the Marlins.

This chapter is now as closed as Perez’s path back to the rotation. Perez is as dead to the Mets as the guys on the face of the currency worth $20 million they’ll be forking over to the left-hander.

But the Mets are alive with the sound of winning baseball, at least at Citi Field, where they improved their record to 21-9 (17-4 over their last 21) with an emphatic 6-1 triumph over Florida that featured seven outstanding innings from Niese, a four-for-four from Ike Davis, and a two-for-three from David Wright that included his 10th home run of the season.

These guys can play a little. Manuel no longer seems a temporary employee receiving mail addressed to, “Occupant, Mets’ Manger’s Office.” Now the trick is to take this 9-4 stretch of baseball and use it as a foundation for a winning summer, both home and away.

Now the burden is on management and ownership to ante up and up the ante by declaring their intention to turn this 29-27 outfit into a legitimate contender. Sitting back waiting for Carlos Beltran to return isn’t going to cut it.

This is the time for COO Jeff Wilpon to give general manager Omar Minaya the authority to be aggressive on the trade market and bring the Mets the starting pitcher to join Johan Santana and Mike Pelfrey at the top of the rotation. This is the time for the Mets to make a hard play for Seattle’s dominating lefty, Cliff Lee, who is in the final year of his contract and thus will be a rental.

It’s about pitching, and it’s even more so about pitching in the cavernous ballpark the Mets call home. The Mets have an overall ERA of 3.88, eighth in the 16-team NL. But their ERA at home is 2.74, fourth in the league, and more than a run lower than the 5.18 ERA the staff has posted on the road.

Winning teams identify their strengths and then play to them. Championship teams identify their strengths and build on them. The Mets’ strengths lay in the arms of Santana and Pelfrey, and in the dimensions of their home field.

Obtaining Lee, brilliant late last year and in the postseason for the Phillies following a Cy Young winning 2008 for the Indians, would give the Mets the most daunting top of the rotation in the league.

No one is suggesting that the Mets should empty their cupboard of prospects in order to get Lee, who will turn 32 in late August. We are, however, suggesting that management go to whatever lengths necessary short of that to get it done. We are suggesting that the Mets overlook his status as a rental.

Lee is likely to become the Yankees’ primary free agent target this winter. Once that bidding starts, the Mets simply won’t be able to keep up. No one can when the Yankees want someone.

If the Mets are going to get Lee, they’re going to have to trade for him, just the way they — and not the Yankees — got Santana. Once Lee’s here, he may even fall in love with pitching in the Grand Canyon and decide to re-up.

The non-waiver trade deadline is July 31. The market won’t begin to percolate for another month. But there’s no reason for the Mets to wait. This can’t be about waiting for Beltran. This is the time to declare.

Mr. Lee, with the baseball, on the Citi Field mound.

larry.brooks@nypost.com