After the Seattle Mariners' exciting run to the ALDS last year, expectations for this season were sky-high for the promising, young roster. The team has numerous stars, including the previous Rookie of the Year winner Julio Rodríguez, fan favorite Cal Raleigh, and power-hitting third baseman Eugenio Suárez. However, for this season, none of these players lead Seattle in wins above replacement (WAR) amongst position players on the roster. That designation shockingly goes to Jarred Kelenic, a once top prospect, who has had a breakout season thus far after a rocky start to his big-league career.

Jarred Kelenic was drafted sixth overall by the New York Mets in the 2018 MLB draft straight out of high school as a highly touted prospect. In a controversial move, the Mets traded Kelenic and other top prospects to Seattle in exchange for second baseman Robinson Canó and closer Edwin Díaz. While Edwin Díaz has become arguably the best closer in baseball when healthy for the Mets, Kelenic's career has been the polar opposite.

After Kelenic's hot start to the 2021 season for the Tacoma Rainiers at the Triple-A level where he put up an incredible slash line of .320/.392/.624 in 30 games, he was brought up to Seattle to make his MLB debut. To say Kelenic struggled would be an understatement; he became a shell of his former self at the major-league level. Kelenic batted .181 in 93 games and was immediately optioned back to Tacoma in June of that season. Kelenic lost his ability to hit the ball, as his wide stance made him susceptible to whiffing on offspeed pitches and breaking balls that see such drastic change from the minor to the major-league level.

The following season was the same story. Kelenic started the season with Seattle but spent most of the 2022 season in Triple-A with Tacoma after posting a dismal slash line of .141/.221/.313 in 54 games. In those first two seasons with Seattle at the major-league level, Kelenic's OPS+ suggests he was 34% worse than the league average hitter, an awful stat line for a once prized prospect. To the average fan, Kelenic had been a failure and was written off by many.

Until 2023 happened.

Kelenic had publicly announced that he would be taking the offseason to work on his swing mechanics, as his weight transfer, tight grip on the bat, and wide stance made adjusting to major-league pitches extremely difficult. According to Kelenic's BaseballSavant page, he had swung and missed 40% of breaking balls and offspeed pitches thrown to him, margins that are not up to MLB standards. With the constant fear of whiffing on an offspeed pitch, Kelenic would often be late on the fastballs, popping them up for easy outs, as he sported a 15.5% pop-up rate in 2022. Hitting coaches attributed this because Kelenic tended to swing for the fences, as a massive leg kick on his swing was too long to adjust to the difference in movement and speed of an offspeed pitch.

MLB Insider Ken Rosenthal reported that Kelenic's offseason was spent with his hitting coach Tim Laker, making adjustments to his swing through a looser grip on the bat and a thinner stance. In simpler terms, Kelenic learned how to hit the ball again. The difference and results were immeasurable.

Kelenic's swing and stance adjustments have worked wonders for him. The breakout beat out veteran outfielder AJ Pollock for the opening-day nod in left field and has not looked back since, becoming the everyday starter. He has statistically been the best hitter on an underwhelming Seattle team, posting a positive slash line of .269/.330/.491 while being 31% better than the league average hitter. He is tied for second on the team in home runs with ten behind fellow young star Julio Rodríguez and has the highest OPS on the team with .821. While Kelenic's strikeout rate remains high, he has been barreling up the ball better, as his averages against all pitches increased tremendously. BaseballSavant states that Kelenic's batting averages against non-fastballs were at a .154 for offspeed pitches and .057 for breaking balls for the previous year. This year, Kelenic hits .256 against offspeed pitches and .208 for breaking balls. The improvement is there; his adjustments have allowed him to see the offspeed pitches better, and the numbers show it. Some say the talent had always been there; it was just that Kelenic needed to re-discover how to make contact with the ball again.

The swing and slugging power fans saw in the minors has finally come out, culminating with a towering 482-foot homer that cleared the centerfield bleachers at Wrigley Field; the farthest home run recorded in the StatCast era at the ballpark. The improvements in his swing have allowed him to hit the ball hard, and the results have continued to show.

The production doesn't come solely from his hitting. Kelenic ranks in the 76th percentile for outs above average, meaning that he is an above-average defender out in left field across the entirety of the MLB. Combine his borderline elite defense with blistering offensive production, and you have the recipe for a budding superstar in Seattle. It's safe to say that the Jarred Kelenic breakout season is upon us, and fans across the nation can sit back and enjoy it.

While it is a small sample size, Kelenic's improvement at the major-league level has been undeniable. It's hard to say if he can keep up the pace throughout the rest of the season, but if he continues this production at a high level, the Seattle outfield tandem of Julio Rodríguez and Jarred Kelenic will be a scary one for many years to come.