2014 Statistics: (MLB) 24 G, 12 GS, 75.2 IP, 5.23 ERA, 4.14 FIP, 7.14 K/9, 2.14 BB/9
(AAA) 10 G, 6 GS, 31.1 IP, 2.01 ERA, 1.76 FIP, 10.63 K/9, 2.30 BB/9
2015 Contract Status: Pre-arbitration
Remember how Chase Whitley carried a 2.56 ERA on a 2.75 FIP after seven starts, looking like the best starting pitcher on the staff not named Masahiro Tanaka? Remember how you thought it wouldn't, couldn't, almost shouldn't last? It didn't.
Chase Whitley was brought up to the majors as an emergency patch in mid-May and turned into one of the best Yankee stories of the first half. He fell off hard before reaching the All-Star break, but it was fun while it lasted. With a 15th round pick who wasn't regarded as much of a prospect, any major league production is a plus. He was promoted out of necessity, the rare reliever-turned-starter needed to plug a spot in a rotation wrecked by injuries. This he did, and did well, for a time.
Eventually, of course, the wheels fell off, to the point where Whitley wasn't even of value coming out of the bullpen. It might well be related to his usage; his combined 107 innings between the minor and major leagues represented a career high and is roughly 40 innings more than he pitched in 2013. If this is the case, it didn't manifest itself in pitch selection or velocity, as you can see his velocity tracked by month in the Brooks Baseball chart below.
The little mouse icon under July shows the point where Whitley turned into a pumpkin. As you can see, there hadn't been a clear change in average velocity to that point, nor was there one the rest of the year. Similarly, there is little by way of a discernible trend in pitch movement over the year, certainly nothing in the downward direction as might be expected. Of course, velocity and movement are not the only manifestations of pitcher fatigue, so this hardly rules out what might very well be the cause for Whitley's performance slide.
Another common theory for Whitley's significant and relatively sudden loss in form is that hitters around the league had caught up to his stuff.
This might explain the general uptick in isolated power numbers against Whitley. As can be seen below, batters generally exhibited a higher isolated power average on his pitches - except for his best pitch, the changeup - from the end of June straight through August, which coincides well with his stretch of horror in the major leagues. This increase in isolated power comes largely from an increase in line drive rate, particularly with the slider.
This increase in power against Whitley could be caused by any combination of factors, potentially including fatigue and better recognition of his pitches, but in any case the effect here is likely his sudden inability to get major league hitters out.
What then, of 2015? It appears likely, barring catastrophic injuries in spring training, that Chase Whitley will open the year with in Triple-A as a starter since he proved to be effective in the role for some time. Given the unfortunate regularity of pitching injuries, it is likely that Whitley will be needed in the Bronx at some point during the year. If he manages to keep the ball in the yard a little more often, his overall numbers will look better than they did in 2014, even if the gaudy sub-3 ERA and FIP from the first two months never returns.
Chase Whitley may never turn out to be a mainstay in the rotation, but at the very least he showed enough early this season that he might turn into a solid spare part for short stretches. That certainly has value, and of course it would be a great story if he ends up being more. It is always nice when a Yankee farmhand exceeds expectations placed on him as a prospect; so often we find it going the other way. If not, well, we will always have those nights in June.