Jesus Montero's got nothing (or little) left to prove

Jesus Montero hasn't been the player the Mariners thought they were getting when they traded Michael Pineda to the Yankees.
But the wonderful thing about baseball is youneverknow. Montero's back in Triple-A (again) and he's been hurting baseballs. Which I was reminded of, Monday night:
That's 14 homers for Montero in just 291 at-bats. I'm not going to look up his platoon splits because I don't really believe they're all that meaningful. But I think it's fair to say that if Montero can hit, generally, he can paste left-handers.
Which would be really useful in Seattle! Montero's demonstrated with aplomb that he can't catch, or play first base. But he might be able to hit, and the Mariners' DH's have a collective 564 OPS this season. Which is EASILY THE WORST IN THE LEAGUE.
This seems like an obvious thing, no?