Former Mariners reliever central to Teoscar Hernández trade is calling it a career

Erik Swanson was never the loudest name in any blockbuster, but he always seemed to be standing right next to the headline. For Seattle Mariners fans, his career is tied to one of the more memorable “win-now” swings of the last decade — the trade that brought Teoscar Hernández to Seattle and shipped Swanson to Toronto as the key bullpen piece going the other way. 

On Nov. 20, the right-hander stepped out of that supporting-cast role one last time, announcing on Instagram that he’s retiring from professional baseball and closing the book on a sneaky eventful seven-year run in the majors.

Erik Swanson retires after quietly shaping Mariners and Blue Jays bullpens

It’s a fittingly understated exit for a pitcher who made a living in the margins where front offices build contenders. Swanson’s name popped up over and over again in the transaction crawl: part of a deal involving Carlos Beltrán early in his career, later included in the package that sent James Paxton to the Yankees, and eventually headlining the return when the Blue Jays moved Hernández to Seattle. You don’t get moved that many times unless teams are convinced you can help them win — and for a pretty solid stretch, Swanson absolutely did.

The version Mariners fans will hang onto is the 2022 Erik Swanson, the year he finally stopped bouncing between roles and just became a problem for opposing hitters. Once Seattle committed to him in the late innings, he started blowing guys up with that riding four-seamer and a splitter that fell off the table at the last second. The result was one of the filthiest relief seasons in the league — a 1.74 ERA and a steady hand in a bullpen that helped nudge the Mariners back into the postseason picture.

Swanson’s run in Toronto drove home how unforgiving life can be for modern relievers. The Blue Jays leaned on him for leverage innings and traffic-heavy situations, but over time the mileage started to catch up. A balky arm and a right forearm issue threw his 2025 completely off schedule. He began the season on the injured list, came back without his usual edge, and never really settled in before the club designated him for assignment after posting an inflated 15.19 ERA over six games.

Taken as a whole, though, Swanson’s career looks a lot better than that final line in Toronto. Over seven seasons with the Mariners and Blue Jays, he finished with an 11–16 record, a 4.20 ERA, and 281 strikeouts in 266 innings. He pitched in the postseason, helped shepherd the Mariners out of their rebuild and back into relevance, and filled exactly the role contenders are constantly searching for: a leverage reliever you can hand the ball to without flinching. He might not have been a closer with a marketing campaign, but managers kept giving him the phone when the game was on the line.

And that’s probably how he’ll be remembered in Seattle — not just as “the guy in the Teoscar trade,” but as one of the more successful bullpen projects of the franchise’s recent era, a reminder that player development wins can come from unexpected places. The Hernández deal never truly blossomed into the long-term win either side hoped for, but Swanson’s part of it underscored just how valuable a late-blooming reliever can be in a team’s competitive cycle.

Now, with his retirement official and his Instagram farewell sent, Swanson steps away with a career that was anything but anonymous, even if it often lived in the fine print.