What does one do with a 31-year-old rookie hurler who boasts a 2.93 ERA over the course of 76 2/3 innings?

Try to sell high and wait for the inevitable implosion to occur, most likely.

Well, what does one do when that same pitcher is throwing a 95 mph heater with a devastating split-fingered fastball that has helped him compile an 11.1 percent swinging-strike rate, which ranks amongst the top-30 pitchers in Major League Baseball (min. 50 IP)? What does one do when one recognizes the lack of a platoon split over the past two years?



vs. RHP

vs. LHP

vs. RHP

vs. LHP


























Things become much more complex. The hurler, given away by the title of the piece, is Milwaukee’s Junior Guerra, who twirled 7 1/3 shutout innings against the Washington Nationals on Monday afternoon to further announce his arrival on the big-league scene.

Guerra also owns a .236 BABIP, which is the fourth-lowest mark (min. 50 IP) in all of Major League Baseball. One can marvel at his performance in recent years all he or she wants; however, the right-hander will have to be something truly special to have any kind of hope at sustaining that kind of batted-ball luck. Only three qualified pitchers posted a BABIP under .250 a year ago — Marco Estrada, who profiles nothing like Guerra, and aces Zack Greinke and Jake Arrieta. The idea that Guerra should be expected to sustain this level of performance is borderline insanity.

I’m sympathetic to the argument, however, that the Venezuela native doesn’t have to sustain this type of batted-ball luck to remain an effective big-league pitcher. The notion that a 31-year-old rookie isn’t likely to finish the season with a sub-three ERA is hardly daring to step out on a thin, quivering limb. Fantasy owners are more wondering whether he’s worth picking up in standard leagues—as he only has a 30.1 percent ownership rate in ESPN leagues—or whether he’s worth targeting in deeper leagues as a potential top-50 or top-60 starter.

It’s important to recognize two things: (1) Junior Guerra isn’t a regular 31-year-old rookie; and (2) he has no-hit stuff on the mound and has for quite a while.

Guerra signed with the Atlanta Braves as a catcher when he was 17 years old. He hit a combined .213/.245/.355 in his first three years of the minors and ultimately moved to the mound due to his impressive arm behind the dish. He struggled—as one would expect—in his professional debut as a pitcher. He posted a 6.59 ERA in the lower levels of the Braves’ system. He eventually caught on with the Mets, actually performing very well in the Sally League with a 1.75 ERA, but was released after receiving a 50-game ban for violating the league’s drug policy.

He bounced around between the Mexican League, independent ball, Venezuelan winter ball, and even Italy. Throughout that time, he never lacked stuff, even if his numbers didn’t reflect it. When he pitched for Wichita in the American Association in 2013, his manager said, “He’s got the best stuff in the league hands down. He’s flat out electric.” He was touching 97 mph with his fastball that year and showed his nasty splitter, too.

Still, the right-hander couldn’t find a road back to the majors until the White Sox signed him to a minor-league deal in 2015. He cruised through Double-A and Triple-A (as illustrated in the table above) and ultimately made his big-league debut as a reliever. The Milwaukee Brewers later grabbed him off waivers, and after a brief stint in the pitcher’s hell known as Colorado Springs, he moved into the Brewers’ rotation. And here we are.

There’s a lot to like about Junior Guerra. He gets swings and misses with his fastball-slider combination against righties and has a brutal splitter against lefties. According to Brooks Baseball, the right-hander boasts three quality pitches, in terms of swinging strikes, from the right side:

Description: Screen Shot 2016-07-04 at 8.39.17 PM.png

And against lefties, he has the ever-important out-pitch that keeps many starting pitchers from finding sustainable success.

Description: Screen Shot 2016-07-04 at 8.39.52 PM.png

Our own advanced statistics also take a liking to Junior Guerra. Prior to his dominant start against the Nationals on Monday, he had a 92 cFIP and a 3.35 DRA—which together suggest that he has been better than league-average and is projected to be better than league-average in the immediate future. For fantasy owners, all of this combines to paint a rather rosy picture for the second-half of the season.

But, it must be noted, that cFIP and DRA can only work with the data available to it. We’re little more than 12 months removed from cFIP and DRA suggesting that Taylor Jungmann would be successful going forward. I wrote at BP Milwaukee last June that one should take these statistics with a grain of salt because they were born from a level of command that he had simply not shown throughout his minor-league career. In other words, cFIP and DRA were not working with accurate data as to who Taylor Jungmann really was as a pitcher.

It’s not difficult to see parallels with Guerra, who has shown a tendency to issue too many free passes. He walked more than five batters per nine innings in 2012 between Mexico and Venezuela. The right-hander even walked 4.1 batters per nine innings as recently as last year with Triple-A Charlotte in the White Sox organization. Even this year, Guerra has walked too many lefties, which isn’t surprising, given that his main pitch against them is a split-fingered fastball that can be very difficult to throw for strikes consistently.

In the end, I think Guerra is potentially useful in all fantasy leagues. He has a big fastball, a legitimate out-pitch against opposite-handed hitters, and no visible platoon split over the past two years. Yes, the BABIP is low and, yes, his historical lack of command could result in prolonged rough patches. For the potential price tag, though, he’s absolutely worth it. He could be the good version of Andrew Cashner if the control remains solid enough. Just be prepared for the chance that he’s what Rubby de la Rosa projects to be when he grows up.


Junior Guerra plays on a bad team and has an age profile that will likely scare off a myriad of fantasy owners. That should mean that the price tag isn’t very high. He has all the building blocks of a competent mid-rotation starter who can put together impressive stretches when his command is good. That’s why he’s worth buying. That profile is not often available, especially off the waiver wire, in July. He also displays all the hallmarks of a frustratingly inconsistent hurler who will get bombed over multiple-consecutive starts and torpedo any steps forward that he provided in earlier starts. But, then again, it should be pretty obvious that a 31-year-old rookie pitcher comes with numerous potholes that could give him a flat tire in the very near future. The fact that there’s a path to sustainable success at this point in his baseball career is a remarkable story of perseverance in its own right.

Thank you for reading

This is a free article. If you enjoyed it, consider subscribing to Baseball Prospectus. Subscriptions support ongoing public baseball research and analysis in an increasingly proprietary environment.

Subscribe now
You need to be logged in to comment. Login or Subscribe