What’s Next For Jesus Aguilar?

On February 2, 2017, the Milwaukee Brewers claimed Jesus Aguilar off waivers from the Cleveland Indians. For Aguilar, who had previously been blocked by fellow first base/designated hitter types like Carlos Santana and Mike Napoli, this represented a new opportunity. He made the Brewers roster out of spring training and served as the right-handed half of a platoon at first base with Eric Thames. In his rookie season, Aguilar posted a solid 114 wRC+ and teased his power potential by hitting 16 home runs.

The following season, Thames tore the UCL in his left thumb. This opened the door for Aguilar to play regularly at the big-league level for the first time in his career. The Venezuelan native responded with an All-Star season. His power came out in full force; he lead the National League in home runs at the end of the first half and finished the season with 35 long balls. When all was said and done, Aguilar slashed .274/.352/.539 (134 wRC+) and was worth 3.1 Wins Above Replacement according to FanGraphs. No one expected another All-Star performance out of him, but he looked as though he would be capable of holding down the fort at first base in Milwaukee for a few more seasons.

Unfortunately, that was not the case. Aguilar’s plate discipline improved in 2019, but his power disappeared. Thames quickly reclaimed the first base gig as his teammate struggled to get going. After Aguilar slashed just .225/.320/.374 in 262 plate appearances, the Brewers decided that they had seen enough. He was dealt to the Tampa Bay Rays at the trade deadline. The struggling slugger finished the campaign with an 88 wRC+, was left off of Tampa Bay’s postseason roster, and was designated for assignment in December.

The rebuilding Marlins decided to take a flier on Aguilar, and he enjoyed a nice rebound in the shortened 2020 campaign. In 51 games (216 plate appearances), he produced a solid .277/.352/.457 slash, good for a 121 wRC+. That performance earned him a one-year, $4.35 million contract to avoid arbitration. Has Aguilar returned to form? There’s a lot to unpack from his four full MLB seasons, so let’s dive in.

 

How Aguilar Has Changed

 

Aguilar’s profile has gone through some changes since he first broke into the league, so the best approach is to break things down year-by-year.

As a rookie, Aguilar’s power was evident. His strong hard hit rate, barrel rate, and xwOBAcon helped him post a .240 ISO. That would have been the second-highest ISO on the Brewers roster had he logged enough plate appearances to qualify. The former prospect’s natural strength allowed him to strike the ball with authority when he made contact. His greatest limitation was his high strikeout rate, which contributed to a merely league-average DRC+ that was thirteen points lower than his wRC+. Because of Aguilar’s underwhelming plate discipline and on-base percentage, much of his value came from his power. His .337 BABIP seemed unsustainably high at the time, and hindsight confirms it. Improvements needed to be made if he wanted to stick at the highest level of professional baseball.

In 2018, Aguilar elevated his game. He reduced his strikeout rate to a more manageable 25.3%. Most importantly, he excelled at two things: pulling the ball in the air and torching fastballs. According to FanGraphs, Aguilar’s overall pull rate increased from 37.1% to 44.1%. His fly ball and line drive rates increased, and he slashed his ground ball rate from 41% to 35.4%. The slugger posted a .833 wOBA on pulled fly balls, which accounted for 13.6% of his batted balls. On top of it all, he sustained his hard hit rate, barrel rate, and xwOBAcon from the year prior. His .424 wOBA against fastballs ranked 12th among hitters who saw at least 1,000 heaters.

In 2019, instead of excelling in the quality of contact field, Aguilar was merely average. On top of that, he dealt with some bad luck. His .272 BABIP was a career-low, and his .336 xwOBA and 104 DRC+ indicate that his performance was actually league-average. Either way, his pull rate fell to lowest of his career, and his ground ball rate ballooned to the highest it had ever been. Ground balls are Aguilar’s worst nightmare. He is consistently near the bottom of the sport in sprint speed, so he’s not going to leg out any infield hits. Finally, he pulled the ball in the air only half as often as he did in 2018 and saw a notable drop in his hard hit and barrel rates.

That brings us to the 2020 version of Aguilar, who looks strikingly similar to his 2019 counterpart in several categories. His hard hit, barrel, and fly ball rates remained the same, and his xwOBAcon decreased even further. His .181 ISO was also much closer to 2019 than to 2018. How did he experience an uptick in performance? While he did not hit the ball with the same authority he used to, Aguilar made three adjustments that enabled him to be productive.

1. He continued to cut down on strikeouts
This was a continuation of the trend that began in 2018. For the first time in his career, Aguilar struck out less often than the average major league hitter did.

2. He slashed his ground ball rate
Aguilar got his ground ball rate back to where it was when he was at his best. Those grounders turned into line drives, which become hits far more often. This allowed Aguilar to bat a career-high .277 and boost his on-base percentage to .352. His .273 xBA lined up perfectly with his results, which is worth noting after Statcast viewed him as closer to a .250 hitter in his previous seasons.

3. He returned to pulling the ball and punishing fastballs
Aguilar has always done the most damage when he pulls the baseball. Prior to joining the Marlins, he had a career .451 wOBA on such batted balls. That remained the case in 2020, when he posted a .432 wOBA on pulled batted balls. Getting back in the habit of going to left field brought positive results.

 

Projecting Aguilar’s Future Performance

 

You could assume that Aguilar’s 2020 approach and batted ball numbers carry over to next season, but making a prediction based on a 51-game sample isn’t the best idea. An alternative is to combine his 2019 and 2020 because of the similarity in several of the underlying metrics. This adds up to a sample of 585 plate appearances, which is close to his 2018 sample. Another option is to scale his career stats to a 162-game season. Relying on Steamer, one of the most reliable projection systems available, to forecast Aguilar’s 2021 season is the safest bet. Here are the results of each method.

Steamer foresees more power returning due to his history, but if the adjustments he made in 2020 stick, Aguilar should still be able to keep himself afloat even if his elite power does not reappear. Either way, Aguilar still has the ability to hit at an above-average clip, and possibly better if he gets hot for a few weeks. Combine that with his positive influence in the clubhouse and low price tag, and you have someone who will still provide value even if he won’t be a three-win player again.

Where Aguilar ends up next year is still not clear. If the National League drops the DH for next season, his path to playing time in Miami becomes muddier due to the presence of Garrett Cooper and Lewin Díaz. The Marlins could opt to give Cooper more playing time in right field after getting a combined 69 wRC+ from their other options at the position last year. They could also deal Aguilar, who has reportedly generated interest from American League clubs. Wherever he ends up in 2021, Aguilar can be expected to post solid, if unspectacular, numbers at the plate with some pop.

Photos by Mark LoMoglio, Dan Sanger, and Kyle Ross/Icon Sportswire | Adapted by Justin Redler (@reldernitsuj on Twitter)