This isn't a new rumor, really. The Mets have long been linked to Brad Miller and Chris Taylor in their search for a new shortstop to upgrade on Wilmer Flores, and now that the winter meetings have begun, that conversation is going to be tossed around again. Expect to hear it a lot.
It isn't the first time the Mets have wanted a shortstop from the Mariners. Adam Rubin is dialed in, so he's to be believed when he says the Mets have had discussions for Miller and Taylor. But he's also writing from the Mets perspective, which means the interest is could very easily be from their side. Calling the Mariners, asking for Brad Miller, and having the Mariners say "no thanks" is technically a discussion, after all. There's no indications that it's been anything more than that. If I were running the Mets, I'd want Miller at basement value too.
After the trade for J.A. Happ, there isn't really much of a match here, at least not with the Mets. The Mariners currently roster six starting pitchers, which is the biggest position the Mets seem capable of dealing from. Juan Lagares is still a person of interest, but with Austin Jackson holding down center field, he isn't quite the fit he would have been last offseason. Still, coming off a 3.8 win year, he'd be a more than adequate return for Miller or Taylor, which is what makes it highly unlikely. Getting a pitcher in return could allow them to trade one of their current pitchers for help elsewhere, but that's starting to get a little cute and presumptuous.
Outside of Lagares, the Mariners would probably need a third team to facilitate something to fill their needs, which seems unlikely -- though if it were to happen, the winter meetings are a fairly reasonable place for that to occur. At this point, this rumor seems entirely from the Mets side, and there's not enough legs to discuss it much further, at least not until we hear the Mariners might actually want to tango.
The Mariners shouldn't be particularly inclined to move Miller or Taylor regardless -- both have plenty of concerns going into 2015, but rostering both of them reduces some of those worries. Miller's power makes his upside continually tantalizing, and he quietly had an excellent second half in a heavily-platooned/infrequent role across 42 games. Chris Taylor's rookie campaign was good in his own right (103 wRC+), but was aided by a whopping .398 BABIP. If the Mariners do choose to sell, there's possibly more value in selling high on Taylor as opposed to selling low on Miller, despite last year's results.
It all goes back to last week's discussion about trading vs. holding and buying free agents. There's unfortunately a high probably that one of Taylor or Miller tanks in 2015, and it's important that the Mariners are prepared for things to fall apart. The Mariners accumulated 3.0 WAR from their shortstops last year, and having both Miller and Taylor together is the reason. Simply having the depth to ride the hot hand added a win or two to the M's, allowing Miller to get his mojo back in the 2nd half while Taylor BABIP'd himself into solid production. The Rockies, owners of Troy Tulowitski and his monster 2014, only accumulated 2.9 WAR because they were miserable at short (-2.2 WAR) after his injury. Depth matters tremendously.
If the right deal isn't there, then the Mariners should hold. Having shortstop depth, especially quality talent that's cheap and club controlled is a huge luxury. It isn't wasted if they roster both Miller and Taylor to start the year. Miller might not become the star he has the potential to be, and Chris Taylor might be a fluke, but having high upside at a premium position shouldn't be cast aside for minimal upgrades.