Mariners News: Former AL West rival expands Seattle's pitching depth

The Seattle Mariners have a new pitcher in their midst, and fans may recognize his name and likeness from his time with an American League West rival.

As the Mariners announced via X (formerly Twitter) on Sunday, they've claimed right-hander Seth Martinez off waivers from the Miami Marlins. He was formerly with the Houston Astros between 2021 and 2024, for whom he posted a 3.93 ERA over 111 appearances.

To clear space for Martinez on the 40-man roster, the Mariners placed right-hander Jackson Kowar on the 60-day injured list. Kowar underwent Tommy John surgery last March. He has been throwing during spring training, but will nonetheless be sidelined for the first two months of the 2025 season.

Introducing Seth Martinez to Mariners fans

The 30-year-old Martinez is already an unlikely major league success story. He began his pro career as a mere 17th-round draft pick for the then-Oakland Athletics in 2016, eventually landing with the Astros via the Rule 5 draft in 2020.

His best work for Houston happened in 2022. Though he did not partake in the Astros' playoff run to the World Series championship, he left an impression in the regular season by logging 38.2 innings over 29 appearances and pitching to a 2.09 ERA.

Martinez's breaking ball was a real weapon in 2022, holding opposing hitters to a .167 average with a Run Value of plus-three.

Martinez was unable to replicate his '22 success in 2023 and 2024, making 79 total appearances but posting a modest 4.33 ERA. His fastball velocity for 2024 was down 1.1 mph from 2022, and that breaking ball got tagged for five of the seven homers he gave up.

However, there may be something for the Mariners to salvage with Martinez. He has joined a team with a culture of experimentation on the pitching side. And if nothing else, he could be a good platoon option out of the bullpen. Right-handed batters have just a .198 average against him for his career.

How Martinez fits in the Mariners' depth chart

Though you never know when an injury is going to shake things up, it appears that Martinez is on the outside looking in at the Mariners' bullpen. Per RosterResource, he does not project to crack the eight-man mix.

However, Martinez does have an opening to make his case as the right long-relief option for manager Dan Wilson. The spot seems to be in the hands of Carlos Vargas, who did not make any appearances in the majors in 2024.

As both Martinez and Vargas are out of minor league options, neither can be sent to the minors without first clearing waivers. This is therefore a competition with real stakes that Mariners fans will want to keep their eyes on as the rest of spring training unfolds.