There’s a quote in the Gemora that says (paraphrased, don’t have it in front of me), referring to Moshiach, “if he’s from the living, he’ll be someone like king …, if he’s from the dead, he’ll be Daniel” (referring to the prophet). So apparently the Gemora says he can be from among the dead tzaddikim. Formally, there’s no halacha one way or the other, though the Rambam (in hilchos melachim umilchatonim, chapter 12 I think) clearly writes that death disqualifies a potential moshiach.

So I’d say there’s at least a minority position that it’s possible. Naturally, because of xianity, it’s not an area that’s emphasized.

Combine that with last year’s Red Sox World Series win and the fact that the Mets haven’t lost every single game this season and it makes a compelling case.