It isn’t that Daniel Murphy doesn’t have value to another team in a straight trade; it is he won’t be able to bring back much in return by himself.
With the Mets’ greatest need power; Murphy is a line-drive gap hitter with limited power. To acquire a 30-homer bat, the Mets would have to sweeten the pot considerably. That would mean dealing one of their pitchers. The Mets don’t want to trade Matt Harvey, Zack Wheeler, Noah Syndergaard and Jacob deGrom, as that is their core.
The most likely pitchers they’ll offer are Jon Niese and Dillon Gee. Perhaps both. That probably won’t get it done, either.
The way I see it, to get a power bat the Mets must spend in the free-agent market or offer more in a trade. Because past history indicates they likely won’t do either, I see them hoping for bounce-back seasons from David Wright and Curtis Granderson, and improvement from Lucas Duda to get their power.
Otherwise, they’ll probably come back next season with roughly the same team.