Just some food for thought, but Brent Suter might be something.
His repertoire reminds me a little bit of that of Kyle Hendricks, except Suter throws a slider instead of a sinker, in addition to the 86 MPH-4SFB, CH combo. According to Pitch Info, Suter does possess a curveball, though, like Hendricks, it's seldom used. They both rely heavily on the fastball (70% usage).
Suter's fourseamer has a K rate over 20%, while the slider induces whiffs at a 22% rate. The changeup, unfortunately, lags behind at 13%, but it's probably because there's only a 5 MPH difference between it and his fourseamer, allowing hitters to tee off on it so far to the tune of a .571 AVG.
If Suter could shave 2-3 MPH off of his CH, he'd likely have hitters well out in front of it, subsequently leading to a few more whiffs and a pretty deadly pitch mix.
I hope he figures it out, because if he does he could be here to stay.