After a series of offseason moves that left their fans mostly underwhelmed and a little more than irritated, the Mets made their first big free-agent splash Tuesday, coming to an agreement with outfielder Jason Bay, Newsday confirmed.

The signing, first reported during Tuesday's Mike Francesa show on WFAN, is expected to be announced next week if Bay passes his physical.

Bay, 31, had been mulling the Mets' offer, which was for four years and about $65 million, for several weeks but his reticence to accept, combined with few other teams seriously interested, fueled speculation he simply didn't want to play in New York.

The numbers the parties are believed to have settled on are for roughly the dollar figures - $66 million - he was originally offered with a vesting option for a fifth year, which may have been at the crux of the delay.

A message left on general manager Omar Minaya's cell phone, on which the voice mail said he wouldn't be available until Saturday, was not immediately returned.

The 6-2, 200-pound Bay, who is expected to start in left, hit .267 last season in Boston with a career-best 36 homers and 119 RBIs. He had a .384 on-base percentage and a .537 slugging percentage.

advertisement | advertise on newsday

Bay strikes out a lot - he had a career-worst 162 last season and had at least 129 in each of his previous seven seasons - and he is not known as a strong fielder, a potential problem in expansive Citi Field.

Some speculate those dimensions might hurt Bay at the plate as he leaves hitter-friendly Fenway Park.

Bay, however, did have plenty of productive years with the Pirates, starting in 2004 when he hit 26 homers and had 82 RBIs and won the National League Rookie of the Year award. Bay, a pull hitter, has hit 30-plus home runs and recorded 100-plus RBIs four of his last five seasons, production the Mets desperately need from the middle of the lineup.

This will be his second tour with the Mets as Bay was in their system in early 2002, acquired from the Expos, before being traded to the Padres for pitchers Jason Middlebrook and Steve Reed.

The Red Sox, who acquired Bay midseason in 2008 from the Pirates, were interested in retaining the leftfielder but their final offer, four years for $60 million, was rejected.

Mets videos

At the time, Bay's agent, Joe Urbon, told foxsports.com: "We don't agree with their evaluation of the player. Frankly, we have other offers on the table that are of greater interest to Jason."

Those offers, beyond the Mets', never were reported and when Bay didn't jump right away at theirs, it started a drawn-out process that fanned fans' frustrations all the more.

But as the weeks went on, it became apparent the market for the outfielder, particularly at the proposed price, was limited. The Yankees, also in need of a leftfielder, never seriously considered Bay.

The Bay signing, if it goes through, would fill one of the major needs the Mets brought into the offseason. They still have others, most glaringly in the starting rotation, which they expect to address after the new year. Righthander Joel Piñeiro is at the top of their wish list for rotation help, though the Mets are balking at his demands of a four-year, $40-million contract.

The Mets also continue to work at coming to terms with catcher Bengie Molina, with the sticking point guaranteed years. The Mets offered Molina a one-year deal for $6 million with an option for a second year and don't seem inclined to better that.

advertisement | advertise on newsday

With Ken Davidoff