Wisler's fastball is plenty good, 93-94, and he's hit his spots in the past. He's got to develop something that gets them off his fastball, probably the change, and then have the guts to throw it in fastball counts. Not a curveball/slider, he's got an excellent slider. But a straight change, or maybe a splitter.
Lil Guv is at the age now where he needs something else, but he has never gotten the deception of the change, at least not consistently. He was screwing around with a splitter in a bullpen and threw five in a row that sunk like a stone 20 feet from the plate. He's using that as a change of sorts, and it's working. Makes his very-good-but-not-Scherzerian fastball look explosive.
Then Wisler can throw the fastball with a little more confidence, and I think the whole thing would come together for him. I still like him. It's hard to spin a ball the way he does that slider. That's a pitch you build around. And I think his fastball's good, too.
The guy needs a change or a change substitute. You might as well send him down and let him work with your best pitching coach, whether that's in Florida, Gwinnett or Rome. He's useless until he figures this out. But if he does, he can still be really good.