Quintana has allowed a total of 12 earned run over two starts without getting to the fifth inning in either one.
SB Nation's White Sox blog, South Side Sox took at look at pitch velocity and location to determine if Quintana was hitting a wall.
Velocity hasn't really changed, but his pitch selection and location hasn't been the same. From South Side Sox:
Along with the lack of a credible changeup, he also isn't showing a consistent ability to backdoor his curve, or what's left of his cutter. When you think of the very good Sox lefties over the last several years -- Mark Buehrle to John Danks to Chris Sale -- they had an ability to work inside and outside with multiple pitches.
Quintana isn't quite there yet. In fact, he looks like he's getting further away, and that could be the sign of tiring. Fatigue doesn't only manifest itself in velocity, but it can take away from sharpness, both in terms of movement and command.
But that doesn't quite cover the narrowing of his pitch selection, and his ability to add and subtract off his breaking stuff. That's the part I think Quintana (or A.J. Pierzynski, or Don Cooper) might have a more specific answer for. He could be wearing down after all, but he might never admit he's tiring to the media, and he might be smart for doing so.
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