Junior Guerra looking to thrive in new role, with new pitch

The split-finger fastball is the pitch that got Junior Guerra to the big leagues.

As the story goes, Guerra learned how to throw the split from former big league reliever Jean Machi while the two were pitching in winter ball in Venezuela in 2009. Guerra spent the next five years working in unaffiliated leagues around the world to master the offering before hooking on with the White Sox and debuting in the big leagues in 2015 at age 30. When he was designated for assignment the following offseason, it was Guerra’s signature splitter that caught the eye of newly-minted GM David Stearns and the analytics department of the Milwaukee Brewers. A waiver claim was placed, and Guerra joined the organization as the first player ever acquired by the Stearns regime.

Guerra has been somewhat of a fixture in Milwaukee’s rotation for the past three seasons since then, taking the ball for 60 starts among his 72 appearances and tossing 337.0 innings with a 3.87 ERA (109 ERA+). But he’s preparing to fill a new role for the club this spring, seeking a spot among Milwaukee’s cache of relievers after pitching so well out of the bullpen in September and the playoffs. And, after adding a deadly curveball to his arsenal late last season, Guerra is attempting to add another change-of-pace to his repertoire this spring.

“I’m trying to throw a changeup right now...I think it’s close. My split the last two years hasn’t worked really good, that’s why I want to learn a four-seam changeup. It’ll look the same as my fastball. The process is really good. I think it’s really close to getting into my delivery.”

The numbers do bear out diminished effectiveness of Guerra’s splitter over the course of his three years pitching in the Cream City. His split was valued at +4.7 runs in 2016 by Pitch Info, followed by +1.7 runs in 2017, then a mere +0.8 runs in 2018. Batters managed only a .150 average off the splitter last season and Guerra generated a healthy 19.35% whiff rate with the offering, but he was able to find the strike zone with it only 22.58% of the time, the lowest rate of any of his pitches. The pitch is also thought to be tough on the arm and the elbow, and Guerra has indeed missed time with elbow soreness in both 2016 and 2018. His overall effectiveness was greatly diminished after missing time nursing his elbow last July, and the loss of control and confidence in his splitter is what prompted Guerra to adopt his new curveball down the stretch.

So Guerra (along with fellow Venezuelan native Jhoulys Chacin) is looking to replace his split-finger and adopt a more standard changeup in camp. He made his Cactus League debut on Sunday and fired off a couple of cambios during a scoreless inning that featured an infield single allowed and a strikeout. Guerra, who pitched for Team USA in the Japan All-Star series and then made a handful of LVBP appearances in Venezuela during the winter, came out firing bullets and caught the eye of his manager.

Guerra is out of options (which Adam McCalvy confirmed with the front office at my request) and will have to win a spot on this year’s Opening Day roster, though his track record and the org’s penchant for prioritizing depth should help him crack the bullpen when the team heads back north to the Menomonee Valley. Still, the 34 year old right-hander is taking nothing for granted.

“If [Counsell] needs me in the bullpen, I’ll be ready for that. I’ll be ready for any situation...All my career, I’ve never known what (my role is). The best thing is I feel really healthy this year.”

“I feel ready, and I think I can help the team in any role. In the bullpen, you have to be ready in any game, in any inning. You have to be ready when the phone rings.”

If all goes according to plan Our Hero, we could see the hashtag #JuniorGuerraDay flashing across Twitter 50+ times this season. With his ability to throw multiple innings, perhaps a role as the right-handed complement to Josh Hader in the middle innings is in the offing?

Statistics courtesy of Fangraphs and Brooks Baseball