Right-hander Trevor Rosenthal officially joined the Nationals this week. He sat out last season as he recovered from Tommy John surgery. He arrives with the Nats after six seasons pitching for the Cardinals.
His pitching repertoire over the years has included a four-seam fastball, circle grip changeup, slider (or cutter) and a curveball. As he finally returns to pitching in the big leagues, Rosenthal said he won’t make any major changes to the type of pitches he throws.
“I am pretty much going to be the same as far as my repertoire,” Rosenthal said today during a conference call. “Mechanically, I have been working on a few things that I have learned. Just biomechanically how to use my body’s energy more efficiently, and obviously with improved strength and conditioning and all that I took advantage of during this time off. I think this will help me over the longevity (of my career).”
Rosenthal pointed out that advanced technology has allowed him to focus on the spin rate of his breaking pitches.
“I have been just using the technology and working on the spin of my breaking ball,” Rosenthal said. “Just trying to enhance my breaking ball. My fastball is kind of going to be what it is and my changeup is going to be there as a primary weapon as well.
“So I think everything is going to similar to what we’ve seen in the past, but hopefully just a little bit extra time and work always trying to improve and make everything a little bit better.”
FanGraphs.com showed in 2017 that Rosenthal did not use his curveball and instead implemented his cutter much more frequently.
According to BrooksBaseball.net, Rosenthal’s four-seam fastball reached 99 mph and produced “extremely high amount of swings and misses” compared to other pitchers’ four-seamers. He also mixed in an 87 mph slider and 88 mph circle changeup
Rosenthal said he couldn’t tweak any of breaking pitches early in Tommy John rehab because he had to be careful about first building strength back in his shoulder and arm.
“Yeah, that’s kind of my plan right now,” he said. “And that’s what I was working on. I wasn’t able to work on it a bunch early on in the process because I was just throwing and playing catch. Just getting the volume up in my throwing.”
Now with the advanced technology knowledge on spin rates, Rosenthal said the Nationals will ramp up the re-implementation of his breaking pitches as he closes in on heading to West Palm Beach for spring training.
“Towards the end (of rehab), I started using some different technology looking at the spin axis and all these different things that I didn’t have a lot of information on before,” he said. “I’m hoping those few weeks that I did that, and the weeks to come leading into spring training, I can dial in to that a little bit more.
“Hopefully (I can) understand it and make some adjustments, definitely get more of a true breaking ball, whether it’s a slider, a cutter, a curveball. But (now it’s) something that I fully understand what it’s doing and able to repeat it consistently.”