Mariners could be in position to deal from starting pitching depth

Going into next year, the Mariners have considerable depth in their rotation. Luis Castillo and Robbie Ray are locked in for the foreseeable future on nine-figure contracts, while both Logan Gilbert and George Kirby proved this season that they fit right in as capable starters who can take the ball in the playoffs. One might expect Chris Flexen, coming off a solid season at the back of Seattle’s rotation that saw him vest an $8M option for the 2023 season, to bring up the rear.

However, it’s also possible the M’s look to deal Flexen for help elsewhere on the roster this winter. As part of a reader mailbag, The Athletic’s Corey Brock notes that multiple teams inquired about the right-hander at this past trade deadline. Brock opines the M’s could more earnestly shop Flexen for offensive help over the offseason.

After coming over to the Mariners from South Korea during the 2020-21 offseason, Flexen had a strong first season in Seattle that surpassed expectations. He made 31 starts, posting a 3.61 ERA in 179 2/3 innings while compensating for his low 16.9% strikeout rate with a minuscule 5.4% walk rate and a knack for avoiding barrels. Because of this, his performance was generally backed up by the peripherals, leading to a strong 3.89 FIP in 2021.

While those numbers are sufficiently impressive one might assume Flexen is a lock for a rotation spot next year, his follow-up to that campaign in 2022 was less impressive. While his 3.73 ERA this season may not seem like a significant departure from last year, due to the drastically more pitcher-friendly run environment this season, his ERA+ dropped from a solidly above average 114 in 2021 to a just a touch below league average 99 in 2022. Flexen’s dip in performance is further explained by regression in all of his peripherals this season: His groundball rate plummeted from 42.4% in 2021 all the way down to 33.8% in 2022, his walk rate jumped up to a still solid but less impressive 8.6%, and his FIP ballooned up to 4.49. All this lead to the Mariners moving Flexen to the bullpen following their acquisition of Castillo at this season’s trade deadline.

It would certainly make sense for the Mariners to entertain offers on Flexen, particularly with the glut of options the Mariners have for the back of the rotation. Marco Gonzales made 32 starts this year and is under contract for another two seasons (with a club option thereafter). Seattle could theoretically shop Gonzales this winter instead of Flexen, but they elected to stick with the southpaw over Flexen as the No. 5 starter down the stretch. The M’s also have promising young arms such as Emerson Hancock who may be ready to make the jump to the majors next year.

Between Flexen’s $8M salary for next season and his dip in performance during 2022, the Mariners wouldn’t recoup an astronomical return. There’ll be a fair number of back of the rotation, innings eating arms in free agency. Many of those pitchers will require multi-year deals, while Flexen will be a free agent after 2023. That shorter commitment could make him more appealing than a free agent landing multiple years at a similar annual salary, but the number of available alternatives will cut against the quality of the trade package Seattle receives.

Given this, the best fit for a Flexen trade would likely be a budget-conscious team who has a bat either under contract or arbitration control at a price higher than they would like to pay. One possible example of such a situation would be the Guardians and Amed Rosario. As Steve Adams discussed earlier Monday, Rosario is projected by MLBTR contributor Matt Swartz to make $9M in arbitration for the 2023 season, and the Guardians have a glut of young talent available, such as Gabriel Arias and Brayan Rocchio, who could potentially be cheaper options to pair with 2022 breakout star Andres Gimenez up the middle.

Rosario, who hit .283/.312/.403 (103 wRC+) this season, has primarily played shortstop to this point in his career, but would surely represent an upgrade over Adam Frazier at second base. Meanwhile, the Guardians might appreciate a durable, back of the rotation pitcher who’s already swung between the bullpen and the rotation in his career to line up behind Shane Bieber, Triston McKenzie, and Cal Quantrill in the rotation, leaving the likes of Aaron Civale and Zach Plesac to compete with youngsters like Konnor Pilkington and Cody Morris for the fifth spot in Cleveland’s rotation. The Guardians aren’t likely to jump at a one-for-one swap of Flexen and Rosario, but it’s possible they could have interest in a bigger trade package that sees those players swap teams.

The Guardians represent just one possible option in this mold, however. The Orioles could be open to dealing some offensive talent to shore up a rotation full of question marks. The Rays may look to move on from first baseman Ji-Man Choi, who could replace Carlos Santana in the DH spot next year for the Mariners. Those are just a few of a number of teams that could be in touch with president of baseball operations Jerry Dipoto and his staff about Flexen this winter.