Arizona Diamondbacks Game Preview, #29: Battle of the fireballers

Rubby De La Rosa RHP, 3-3, 4.18

Jose Fernandez RHP, 2-2, 4.08

Phil Gosselin - 2B	J.T. Realmuto - C
Jake Lamb - 3B	Martin Prado - 3B
Paul Goldschmidt - 1B	Christian Yelich - LF
David Peralta - CF	Giancarlo Stanton - RF
Brandon Drury - RF	Derek Dietrich - 1B
Yasmany Tomas - LF	Marcell Ozuna - CF
Chris Herrmann - C	Adeiny Hechavarria - SS
Nick Ahmed - SS	Miguel Rojas - 2B
Rubby De La Rosa - RHP	Jose Fernandez - RHP

Both men here are the hardest throwers in their respective rotations, and rank in the top 15 for fastball velocity across all major-league starters (min 10 IP). Fernandez, at 94.8 mph is #8 overall; De La Rosa isn't far behind, at #14, and has had an average fastball this season of 94.4 mph - only Archie Bradley in his one start came close to that for Arizona, and the mean across our entire rotation has been 92.5 mph. Here's how it breaks down so far for the Diamondbacks, with the figure in brackets representing the same figure in 2015:

1. Rubby De la Rosa: 94.4 mph (94.3)
   
2. Archie Bradley: 94.3 mph (92.2)
   
3. Robbie Ray: 92.9 mph (93.3)
   
4. Shelby Miller: 92.3 mph (94.0)
   
5. Patrick Corbin: 91.6 mph (92.4)
   
6. Zack Greinke 91.1 mph (91.8)

Some interesting changes there, though perhaps the lack of change for Rubby is most notable, considering how impressive his last couple of outings have been. Bradley's velocity was certainly higher, though the results show that merely throwing harder isn't necessarily going to lead to better performance. However, I note that Miller, and to a lesser extent Corbin and Greinke, are experiencing downticks in their velocity, and it's possible these might be a factor in their struggles. Is Miller trying to compensate for a perceived lack of control by "guiding" the ball to the plate, only for that actually to compound the problem? But I'm just speculating there.

Lamb back in the line-up today for Arizona, but Jean Segura is still out. According to Nick P, Jean "says he feels better but not 100 percent. Doesn't want to risk a setback this early in season." Probably wise. We also see Herrmann catching De La Rosa, which would appear to make sense after the last couple of outings, where they seemed to work well together. It's an important start for Rubby, as he seeks to establish that the good results of the last two outings were not merely his usual random fluctuations. Has the Wheel O' De La Rosa got stuck on "good outing"? We'll keep our fingers crossed for evidence in that direction from this afternoon.