Last winter, the Arizona Diamondbacks signed Zack Greinke to a monstrous six-year, $206.5 million contract after he lead the league with in ERA (1.66), ERA+ (222) and WHIP (0.84). It would've been foolish to expect that kind of production from him as a 32-year-old, but they likely weren't anticipating what actually happened.

The veteran right-hander hadn't produced an ERA (4.37), FIP (4.12) or WHIP (1.27) that high since his days with the Kansas City Royals, and his performance in April probably gave the Arizona front office immediate buyer's remorse.

Greinke's ERA for the month settled in at 5.50 with a .361 wOBA over 37.2 frames. If there were some reasons to feel optimistic that things would settle down, though, all we'd have to do is look at his FIP in April, which was almost two runs lower than his ERA (3.81). He also had an abnormally high .347 BABIP allowed (just .298 for his career).

This did get better for him once May arrived, as he went a combined 8-1 over the next two months and looked more like the pitcher Arizona ponied up a bunch of money for before hitting the disabled list.

But, like Wainwright, he didn't finish on a high note (6.02 ERA, 5.52 FIP in his final 49.1 innings) and there are concerns about him this spring, which are mostly centered on his diminished fastball velocity.