Mariners officially sign Stanek, but Jackson Kowar out for year

Mar 10, 2024, 12:30 PM | Updated: 12:43 pm

Seattle Mariners Jackson Kowar...

Kansas City pitcher Jackson Kowar throws against the Seattle Mariners in a 2021 game. (AP Photo/Charlie Riedel)

(AP Photo/Charlie Riedel)

There is a little more clarity on the shape of the Seattle Mariners’ bullpen for 2024, but it comes with bad news.

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The M’s officially signed veteran right-handed reliever Ryne Stanek on Sunday after he passed a physical, confirming reports that first broke on Friday. But with Stanek’s addition is also the confirmation of the reason he has entered the fold: Jackson Kowar, a promising bullpen candidate, is headed for Tommy John surgery.

Kowar has been placed on the 60-day injured list with a right ulnar collateral ligament tear. Mariners general manager Justin Hollander said Sunday that Dr. Keith Meister will oversee the surgery next Friday in Dallas to repair Kowar’s UCL, per Mariners reporter Daniel Kramer of

The Mariners acquired Kowar from Atlanta in December in the trade that sent Jarred Kelenic, Marco Gonzales and Evan White to the Braves. The 27-year-old Kowar has largely struggled at the big league level since making his debut in 2020 with the Kansas City Royals, but the former first-round MLB Draft pick had garnered some hype at M’s spring training with a focus on a fastball/slider pitch mix.

Related: Shannon Drayer on Kowar’s potential with Mariners

As for the 32-year-old Stanek, the hard-throwing right-hander should be familiar to Mariners fans after spending the past three seasons with the American League West rival Houston Astros.

“We are excited to add Ryne Stanek to our club. His combination of high-end stuff and durability adds to an already deep and talented relief corps,” Hollander said in a press release Sunday. “Ryne has a strong track record of pitching in leverage roles for championship-caliber teams.”

For a closer look at Stanek, click either of the links below.

With ‘pen uncertainty, M’s add StanekBreakdown: Who is Stanek?

More Mariners coverage from Seattle Sports

Mariners Notebook: No concern over two key bats’ slow starts
Drayer’s Mariners Notebook: Reliever updates, why AJ Pollock is back
Mariners Odds & Ends: MLB The Show ratings, uniform notes and more
Morosi on Seattle Mariners: Ryan Bliss is a potential rookie to watch
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Mariners officially sign Stanek, but Jackson Kowar out for year