Bay was reportedly set to sign an extension with the Red Sox last summer, but the team and the player had a disagreement over a knee injury. The Red Sox, according to NESN baseball analyst Peter Gammons, wanted to include stipulations in the contract regarding the knee, but Bay disagreed with the assessment.
This week, in an extensive interview with The Boston Globe's Nick Cafardo, Bay shared his side.
"I was told in August that in order to get the reduced deal they were offering I'd have to have knee surgery on something that didn't hurt," Bay told the Globe. "They said, 'We feel like you need it and it will help.' Then they came back at the end of the year and they were willing to [agree to a contract] without the surgery. I said, 'Wait, you thought I needed this surgery a month earlier and now you don't?' And they explained that they felt comfortable with the way I finished up the season and I didn't need it.
"However minor, however major, however [much] gray area, that's what happened," he added. "It was flabbergasting to me how that situation changed. This isn't meant to be throwing stones at doctors, but it got to the point where I needed to answer some of the things that were out there.''
Throughout the entire process though, Bay said the discussions were far from hostile.
"Even while the whole ordeal was going down, they were very cordial,'' he told the Globe. "I was told a number of times before I left by the owner [John Henry and] the president [Larry Lucchino] how much they really wanted me back and to keep [the Red Sox] in mind through this free-agency process. I was kind of scratching my head a little bit after what transpired.
"Ultimately," Bay said, "it comes down to the dollars and all that stuff, but it never really fell apart. … All along they maintained, 'We still want you. Look around and see what you find.' Ultimately I came to this."
"This" was a four-year, $66 million deal with the Mets, with a $17 million club option in 2014.
Bay credited playing in Boston for his ability to garner such interest in the free-agent market.
"It absolutely helped me,'' Bay told the Globe, in reference to his 200 games in a Red Sox uniform. "I'd been toiling in Pittsburgh for six years and [then] overnight I'm arguably in the biggest market in baseball in a playoff race. Everyone who plays in a small- or mid-market team who all of a sudden goes into a big market has to wonder what it's all about and if they can handle it. Was I nervous or scared? No, but I was interested in how I'd react and I was pleasantly surprised."
Bay also told the Globe that he felt like a member of the Red Sox all the way up until the end of the season, when he said he had "a little more power" in determining his future.