Brewers Tender or Non-Tender Decisions: Junior Guerra

2019 salary: $2,225,000
2020 projection: $3,500,000
Difference: +$1,275,000

After three years of starting games or serving as a swingman in the Brewers bullpen, Junior Guerra made a full-time switch to the bullpen in 2019 and ended up putting together one of the best seasons since his breakout in 2016.

His background as a starter helped as he threw 83.2 innings out of the bullpen while appearing in 72 of the Brewers’ 162 games in just about every bullpen role you could imagine, from soaking up innings after a short start to getting high-leverage outs in the middle innings to closing out games when Josh Hader wasn’t available.

Pitching strictly out of the bullpen seemed to have positive effects both on his health -- there weren’t any flare-ups of a forearm injury that led to some elbow worries in 2018, and he was able to throw his splitter 21% of the time in 2019 -- and on his performance, as he allowed baserunners at the lowest rate of his career, setting a new personal best with a 1.12 WHIP and holding opposing batters to a career-low .191 average.

While impressive, there may be some worry on how repeatable that may be. Guerra’s strikeout numbers didn’t increase significantly with the full-time move to the bullpen, but there was nearly a 100-point drop in the Batting Average on Balls In Play he allowed compared to last season. Granted, the .312 BABIP against him in 2018 was especially high, but the .218 BABIP he allowed in 2019 is on the other extreme, especially when compared to his much more normal career average of .266.

That, combined with a rise in his walks in 2019, could lead to some cause for concern on how real his 2019 results were. This is the kind of variability you get year-to-year with relievers, though, working with small samples and trying to figure out what’s real between a one-year spike in walks, a huge drop in BABIP, an increase in groundball percentage and a drop in home run rates in a year where everyone was hitting home runs.

Luckily, Guerra has been around long enough that we — and David Stearns — know roughly what we can expect in 2020. That seems likely to be at the very least a solid middle reliever capable of a multi-inning appearance or two every week, and one you don’t feel too nervous about having to handle a handful of high-leverage moments along the way. That seems to be well worth the minimal cost of about $3 million, considering how heavily the Brewers leaned on Guerra in a variety of situations during the 2019 season.

The fact that Stearns will likely have to replace a significant amount of innings in the bullpen after the completion of Matt Albers’ contract and the expected loss of Drew Pomeranz could also play a role in the decision whether to tender Guerra a contract. With Corey Knebel’s effectiveness after Tommy John surgery still a question mark, removing Guerra from the bullpen equation would be a big gamble without a true safety net beyond Hader in the back end of the bullpen. In terms of Baseball Prospectus’ WARP, the only relievers who provided more value to the Brewers in 2019 than Guerra (1.2 WARP) were Hader (2.6) and Pomeranz (1.6). Nobody ranking behind Guerra even surpassed 1 WARP.

Something else that will likely factor into the decision -- while Guerra isn’t the “optionable” reliever Stearns likes to fill his bullpen with, he still remains under team control through the 2022 season. That very well may take Guerra through his remaining productive years, and given how hard a time Stearns has had in trying to get steady middle relief elsewhere, may make this an easy decision to retain him.

Statistics courtesy of Baseball Prospectus and Fangraphs