Pirates, Diamondbacks have discussed Didi Gregorius trade

Jon Morosi tweets that the Pirates and Diamondbacks have discussed a trade involving shortstop Didi Gregorius.

This doesn't really make sense. The Pirates already have two shortstops on their roster, and there are other teams with far greater needs at shortstop, including the Tigers and Mets -- if you played shortstop in high school, you may want to keep your phone on, in case Dave Dombrowski calls.

Also, this is the kind of stance that could end up looking really stupid, but I'm not sure there's enough evidence that Gregorius is a big upgrade on Mercer anyway. Gregorius' offense last season (.252/.332/.373, already nothing to write home about) was surprisingly good, given his minor-league record, which wasn't at all promising. ZiPS has him hitting .265/.317/.393 in Arizona this season, and being worth three-tenths of a win more than Mercer in a similar amount of playing time. (Gregorius is, it should be noted, clearly the better defensive player, and much of his value hinges on his defense.) Kevin Towers has made some bizarre trades recently, and it isn't as if Gregorius wouldn't be helpful, so there's no harm in calling and seeing if Towers has some irrational love for Jeanmar Gomez or something. But it's hard to see this being a match of need and demand.