2025 MLB First-Half Recap: Seattle Mariners

The Pitching

The Good

Looking back at the 2024 season, the Mariners ranked in the bottom half of the league in several categories, including runs scored. That, however, has not been the case this season.

Seattle’s offense has been humming all season, thanks in large part to All-Star catcher Cal Raleigh. Raleigh entered the All-Star break with a 1.012 OPS, and he leads the league in home runs (38) and RBI (82). He’s on pace to smash Salvador Perez‘s record of 48 home runs in 2021 for the most homers by a catcher in a single season.

Raleigh’s explosion led him to lead the Majors in total slugging percentage change between 2024 and 2025 (.198). And, he’s not the only one who surpassed his 2024 numbers. Jorge Polanco, the oft-injured infielder, ranked eighth (.119).

Aside from those two, the M’s have gotten production from other notables. Utilityman Dylan Moore hit nine home runs in the first half, while Randy Arozarena belted 17 and entered the break on a hot stretch. From June 18 to July 13, Arozarena slashed .323/.380/.677 (1.057 OPS) with nine home runs and 16 extra-base hits across 24 games.

On the mound, All-Star Bryan Woo helped carry the rotation, giving Seattle relief every fifth day. The Mariners have dealt with injury problems, specifically to their rotation, as Logan Gilbert, George Kirby, and Bryce Miller have all spent time on the IL this season.

Miller, dealing with elbow inflammation, is still on the injured list.

And in the bullpen, Andres Munoz was excellent over the first half. Munoz struck out 46 over 36, en route to an All-Star nod. He’s been part of an excellent bullpen, alongside Gabe Speier, Eduard Bazardo, and a healthy Matt Brash.

The Bad

It’s been a struggle to find a castmate to fit with Arozarena and Julio Rodriguez.

Victor Robles suffered a shoulder dislocation in early April, ending his 2025 season after 10 games. Seattle tried Leody Taveras, the ex-Ranger who was cut loose by Texas. Unfortunately, he didn’t provide much value offensively and was outrighted to Triple-A in June thanks to a .470 OPS in Seattle.

Mitch Garver, with a .654 OPS in the first half, has yet to find his stroke in his second season with the Mariners.

Back to the rotation, Seattle’s dealt with injury problems as mentioned earlier. However, Bryce Miller (64 ERA+) and George Kirby (81 ERA+) were not sharp when on the mound. The latter has found his way, though, in June & July after struggling to land his slider early on in the year.

What to Expect in the Second Half

The Mariners are not out of the AL West title race, as Seattle entered the break five games behind the Astros for first.

Seattle was active last summer, as the Mariners landed Randy Arozarena to bolster their efforts both in 2024 and beyond. Thus far, the move’s worked out great. However, another bat to support J-Rod and Arozarena would not be a bad idea.

And, the Mariners’ ownership are reportedly willing to add to their payroll.