Jeff Zimmerman has been thinking about pitcher injuries and velocity spikes for a while. He puts together some interesting research over at The Hardball Times that's worth your time.
For instance, pitcher velocity has spiked over the last decade, but that hasn't led to a corresponding spike in pitcher injuries.
So, velocity is increasing, pitchers are losing the same amount of days as they did more than a decade ago.
Now, this doesn't mean velocity isn't a factor, but it shouldn't be the only reason people look to when it comes to pitcher arm injuries. If I used the same logic, I could say that the increase in fastball velocity has led to a significant drop in shoulder injuries.
Zimmerman then looks at how many pitchers who throw at different velocities get hurt. He finds that pitchers who throw hard are more likely to get hurt, but in the season after they turn up the gas.
The results are not surprising. Pitchers who threw harder were more likely to go on the disabled list than those who didn't. The difference in injury likelihood is not really in play for the season the pitcher threw hard. The real difference is in the next season. A pitcher who throws a fastball harder than 93 mph is almost twice as likely to end up on the DL, for an average of 60 days, than one who throws less than 90 mph. I included the days lost, but there isn't much of a difference between categories or any noticeable trend.
Think about that in the context of Houston's pitching acquisitions. They spent money on Scott Feldman instead of harder throwers. They invested in Collin McHugh, despite his fastball not being incredibly poppy. They traded away a guy with a huge fastball and liked Brady Aiken more than Tyler Kolek, despite the hometown kid having more velocity. That last bit turned out badly, but maybe the Astros are in on this study before Zimmerman was.
This also plays into my theory that the Astros will not spend on a big ace this winter. Instead, I expect them to go after a Doug Fister type, someone who's a very good starter but won't command the same money as the top of the market.