The Ascension of Junior Guerra

Let’s set the stage:

The Brewers were entering the final game of their brutal west coast road trip. Despite being tied or ahead after six innings in six of their previous eight games, our local nine had managed to capture just one of those contests while dropping their record to a season-worst nine games below .500 at 31-40. The club desperately needed a win to salvage a 2-7 road trip and build some momentum heading into an off-day before a six game home stand.

Enter Junior Guerra.

The 31 year old rookie sensation played the role of stopper beautifully yesterday, firing seven innings of five hit, two run ball as the Brewers defeated the Athletics by a score of 4-2. Guerra struck out eight batters against just one walk while lowering his ERA this season to a nifty 3.67. The club now has an 8-2 record in his 10 starts.

Since Juni G entered the rotation on May 3rd, it’s difficult to argue against the fact that he’s been the Brewers’ best starting pitcher, better known as the #2016BrewersAce. Here’s how he ranks against the rest of the staff this season:

3.67 ERA - 2nd
3.86 FIP - 1st
7.78 K/9 - 1st
2.79 BB/9 - 3rd
1.03 HR/9 - 1st
.262 BABIP - 1st
11% Swinging Strike Rate - 1st
1.0 fWAR - 1st

No one (well, besides me) predicted that Milwaukee would be receiving such major contributions from a hurler on the wrong side of 30 who spent the six seasons prior to last year toiling in unaffiliated leagues all over the world. By ERA-, he’s prevented runs at a rate that’s 13% better than league average this season.

There’s really no indication that Junior is going to slow down anytime soon, either. While some might point to his low .262 BABIP, fly-ball pitchers like Guerra tend to have a lower than average BABIP and he’s shown to be adept at producing an above-average amount of pop-ups. He generates plenty of swings-and-misses, especially with his devastating splitter, a pitch that can catch throw hitters for a loop since only 43 of the 582 pitchers that have appeared in the big leagues this year have been recorded as throwing one (according to Pitch F/X data from Fangraphs). Junior’s walk rate, which has plagued him on occasion during his ascension to the big leagues, has been kept well under control. He has great poise and composure on the mound and has certainly carried himself as though he belongs near the front of a major league rotation.

It’s not altogether unreasonable to think that Juni G may improve upon his already impressive numbers, as well. Guerra has certainly followed a non-linear development path, originally signing as a catcher in 2001 and not converting to the mound until 2006 at age 21. Not only did Guerra need to learn an arsenal of pitches to come after hitters with, but he needed to find proper mechanics, had to be taught how to control the run game, how to field a new position, etc. The bulk of this development, including the addition of his split-finger to his repertoire about five years ago, took place while Junior was pitching in independent ball. Now that he’s found a foothold in the major leagues and gets to work with some of the best coaches on the planet on a daily basis, Guerra should be able to continue refining his process and improving his performance.

In spite of his relatively advanced age, Guerra is still a “young arm” in terms of workload, as well. Since he’s only been pitching for about 10 years, he has much less mileage on his right arm than the typical 31 year old would. According to his pitching register at Baseball-Reference, Junior has thrown less than 780 innings during his professional career, or roughly the same amount of pro innings as Wily Peralta had logged by age 23. That should no doubt bode well for Guerra’s chances to defy the typical aging curve and stave off father time while remaining effective as he enters his mid-30s.

Something about the 31 year old with four big league innings piqued the interest of Slingin’ David Stearns back in October, when he was claimed off waivers from the White Sox with Stearns’ first transaction as GM. Thus far, the move has paid off in spades. Guerra has ascended from waiver claim on the fringes of the big leagues to a workhorse starter that is occupying the role of #2016BrewersAce, and there is a distinct possibility that he’ll continue to improve at the major league level.

One never knows where exactly a team will find valuable talent, and perhaps Junior Guerra is on his way to becoming the Brewers’ version of Jake Arrieta - a buy-low pitcher who morphs into an unexpectedly dominant front-line starter.