That was my thought exactly Wily Mo.
The big overhand curve provides a definite clue. On Friday, as it crossed home plate it was dropping at a sharp angle, and it looked like he could command its location at will (the hitters had to dip their back knees to go down with it, as opposed to whaling away belt-high). In this particular game it was a Sele curve.
The 0 walks in 20 preseason innings don't exactly argue against his game-in, game-out command, either.
When the sinker is thrown at a downward angle (from high overhand to hit the knees) it also has an impressive shape to it, like reaching your hands over a barrel to grab something behind it. On Friday the low sinking fastball was every inch a Wang sinker.
Could be the hitters are so focused on dealing with a 'novel' shape on the fastball that they get sort of sensory-overloaded with the -12 MPH yakker.
Super impressive outing. Of course the Colorado game leaves him with 18K in 20IP preseason and we can safely rule THAT out. But can he pitch? The pitcher we saw Friday night is a flippin' good bet to do so.