The Brewers entered rebuild mode as they suffered through a 68-94 season. Trading away veterans who were not nailed down, Doug Melvin set the stage for David Stearns, the youngster GM who will start aging very quickly and continued what Melvin started. Gerardo Parra, Aramis Ramirez, Carlos Gomez, and Mike Fiers were traded during the season, and Adam Lind and Francisco Rodriguez followed after Stearns took over*.
*Wow. I never realized how many trades were involved in this veteran shedding. I might be missing some too.
After so many trades, there are a few vacancies, including in the outfield. Ryan Braun will continue to man right field. Center field will not be manned by newcomer Domingo Santana, which means the Brewers have two capable outfielders to man left field: Khris Davis and Santana.
Davis just turned 28 before heading into his fourth season in the bigs. His nickname, "Khrush", should make it fairly obvious what his primary skill is: power. Davis has a career .244 ISO, which is similar to what Paul Goldschmidt, Todd Frazier, and Lucas Duda put up in 2015. Unfortunately, that power comes with strikeouts. Davis struck out 27.7 percent of the time last year, which would have placed him in the top 10 had he qualified. Davis did take a step forward by walking at a double-digit clip for the first time in his major-league career, and that increase was backed up by a lower rate of swinging at pitches outside the zone.
For all the contact issues Davis has, the 23-year-old Santana has them worse. He's had all of 205 plate appearances at the major league level, but his career contact rate of 64 percent is very low. For reference, Kris Bryant at 66.4 percent had the lowest contact rate among qualified hitters. After being traded to the Brewers, Santana cut his strikeout rate down to 31.7 percent. However, Santana also walked more than Davis. He did not swing much at stuff outside the strike zone in 2015.
Santana also displays power, but it is pretty hard to access that power making contact only 64 percent of the time. If Santana could cut down on the strikeouts a bit more, his extra plate discipline could offset the difference in strikeouts between himself and Davis. However, should Santana's contact issues persist, he will find it difficult to succeed at the major league level.
On the defense side of the ball, these two fellows will battle it out for left field. This is where Santana's offensive deficiencies could outweigh Davis' pluses, even if Santana only maintains his current strikeout rate. Over 2,292.2 innings in left field, Davis has -3 DRS and -6 UZR. The main gripe against Davis is his arm; the Fielding Bible, UZR, and Derek Harvey over at Brew Crew Ball all note a poor throwing arm. Davis might have decent range, but Santana's range is supposed to be better. Santana also has a much stronger throwing arm that Harvey noted could play in either corner. The defensive metrics don't like Santana's debut, but it's such a small sample that it can be ignored for now.
As a total package, Khris Davis has offered something around 1-2 fWAR each year. He is projected in that range again (1.2 - Steamer), so there's not much growing for Davis to do. Santana is projected for 1.6 fWAR in a very similar amount of playing time. Santana is projected for a little less offense, a little better defense; Davis is projected for a little more offense, a little worse defense. That seems like a good summary.
As a much younger player, Santana's ceiling is higher, and he's much more likely to be around for the next competitive Brewers team. However, his contact issues make him a risky proposition. He mashed in the minors, so he probably doesn't have much left to learn there.
In reality, the Brewers are continuing their rebuild. Santana has very little service time accrued, so he won't be a free agent this decade. Davis still has four years of control himself, including 2016. It's actually possible that a veteran Davis could be around for the next competitive Brewers team as well. However, Ryan Braun is here to stay, and the Brewers will try some combination of Keon Broxton and Kirk Nieuwenhuis in center field. Given the current state of the rebuild, Davis is likely auditioning for a midseason trade and keeping the spot warm for the younger Santana. However, given Santana's risk and Davis' not-so-few years of remaining control, the decision between the two is not so clear-cut.