Should the Mariners make a change at shortstop?
Youth must be served. But when and at what cost?
Shortly before his promotion to the majors on May 17, I expressed concern on social media regarding the big-league readiness of Mariners top prospect Colt Emerson. And what set off the alarms for me?
Emerson had a 27.4-percent strikeout rate in 169 plate appearances with the Tacoma Rainiers. To this nerd, the 22nd overall pick of 2023 striking out so frequently against lesser AAA competition was a red flag.
Naturally, my view was not well received by a segment of Mariners Twitter, which is fine. But I believe some of the folks pushing back incorrectly assumed I was criticizing Emerson. I was not. Quite the opposite. My trepidation with his strikeout rate left me wondering whether the team was rushing a 20-year-old to the big-leagues.
Let’s remember that on May 17, Opening Day third baseman Brendan Donovan was placed on the IL. There was a need at the hot corner and there were few viable candidates to fill it. That’s where Emerson entered the picture.
Early in the Ohio native’s stint with the Mariners, the bat was quite impressive. In his first 15 MLB games through June 2, he boasted a .271 AVG, .352 OBP, .583 SLG with three home runs, four doubles, and a 163 wRC+, which essentially says he was 63-percent better than the league-average hitter.
Weighted Runs Created Plus (wRC+) quantifies how a hitter’s total offensive value compares with the league average after adjusting for park effects. League-average is always 100. Therefore, a wRC+ of 150 means a hitter was 50-percent more productive than the average player. An 80 wRC+ would be 20-percent below average.
And Emerson’s strikeout rate? During those initial 15 contests and 54 plate appearances. It was 27.8-percent. Almost identical to what he had generated in Tacoma. Then came the next 36 games.
Since June 3, Emerson has a 35.9-percent strikeout rate and a 35 wRC+ in 128 plate appearances. When we break down his numbers into monthly splits, it becomes evident how much his production cratered as time elapsed.
Some may see Emerson’s June stats and suggest he was still a relatively productive hitter last month. To a degree, yes. But when we consider the last 30 days dating back to June 23, the left-handed hitter has one extra base hit (a home run) and a 20 wRC+.
This rapid decline has resulted in Emerson’s overall season numbers being among the worst in baseball. Since his debut, 199 hitters have at least 150 plate appearances. Within this group, Seattle’s starting shortstop is bottom five in AVG and OBP. He also ranks 194th in strikeout rate and 180th in wRC+.
Some fans may contend Emerson’s defense makes his offensive swoon more palatable. That the glove alone makes him valuable to the Mariners. Perhaps, although Statcast suggests he’s been average during his 36 contests at shortstop.
Emerson has a fielding run average (FRV) of zero. That’s eighteenth best among 27 shortstops with at least 200 innings since his first game at the position on May 19.
Fielding Run Value (FRV) Captures the overall measurable defensive performance of a player or team. It looks at range and throwing for fielders. For catchers: blocking, framing, and throwing are considered. ZERO is always average.
The same subset of the fan base may contend that Emerson’s mid-pack FRV is a big improvement over J.P. Crawford. It’s true that the Opening Day shortstop’s defensive metrics have been on the decline for several seasons. Through the end of May, his minus-6 FRV ranked 29 of 31 shortstops. Only San Francisco’s Willy Adames (minus-8) was worse.
Emerson does represent a major defensive upgrade over Crawford. But in of itself, this fact doesn’t justify keeping him on the big-league roster. Finally, consider the following conventional nugget.
Even though Emerson has played 175 fewer innings at shortstop than Crawford, he has the same number of throwing errors as the longest-tenured Mariner.
True, the error can be a very misleading metric. Unlike Statcast, which doesn’t rely on human judgement, errors are dependent on the opinion of an official scorekeeper. Moreover, a fielder with good range may accrue more fielding errors than someone with lesser range simply because they’re able to reach more batted balls. That said, throwing errors are more credible to me.
Granted, Emerson’s defensive numbers are a small sample. The same is true with his offensive stats. But to me, sending him back to the minors now may benefit both player and team in the long run. It might even pay off later this season.
Just to be clear, I am not laying the Mariners’ offensive woes at the feet of a 21-year-old with 51 games of MLB experience. He’s the number-nine hitter in a lineup loaded with established, talented hitters. Most of whom have fallen down on the job for large portions of this season. Specifically: Cal Raleigh, Julio Rodríguez, Josh Naylor, and Crawford.
Still, what’s in the best interest of the kid?
I realize the people running the Mariners’ baseball operations department are much more intelligent, infinitely better resourced, and way more experienced than me. But I can’t shake the belief that, in Emerson’s case, youth would be better served with a return to Tacoma.
It’s important to recognize Emerson rejoining the Rainiers would not be a sign of failure nor would it be a reason to doubt his potential. Think of it as just a precautionary measure to help keep his long-term development on track.
Remember, a 19-year-old Mike Trout was sent back to the minors for a brief stint during his debut campaign in 2011. He subsequently began 2012 at AAA before joining the Angels. He won Rookie of the Year and was MVP runner-up that same year.
If a future Hall of Famer needed more time, then it’s okay for any youngster to take a pause to reset. Perhaps sending Emerson back to Tacoma will be on the table when Donovan returns from the IL. Then again, why wait?
Regardless of what the Mariners decide to do with Emerson, I’m looking forward to watching him eventually thrive as a major-leaguer whether it’s in 2026 or in the future. He’s clearly talented and well regarded as a quality person.
That makes him super easy to root for.
My Oh My…





