The highlighted point on Dalbec is interesting and makes me think the Red Sox and Mets match up fairly well.
Dalbec is a quality 3b prospect not only due to his power but his defense. The Mets could use him next year.
I would like to see the Red Sox expand the Diaz deal to include Wheeler and D.Smith. To achieve that, it is conceivable that the Red Sox could trade Porcello to a third team (one of the NL teams looking for pitching) for a so-so prospect.
Other players that could be included in a package with the Mets: Duran, Wilson, D.Reyes, T.Ward. It is hard to gauge the Mets interest in a CF--they are considering moving Rosario to CF next year and Gimenez, an elite defender at SS, is already at Double A (his offense is far behind his glove, however).
To make this deal work, maybe take out Wheeler and keep Porcello? In this scenario, the Red Sox would be trading for Diaz and Smith, and the Mets would acquire Dalbec and a few other pieces.
In another media report that I can no longer find, it was suggested that J.Groome could be involved in the deal. I would hate to give up Groome but I would do it for D.Smith: Diaz, Wheeler, and Smith to the Red Sox for Dalbec, Groome, Reyes, and another player.