Potential fit #2: Shota Imanaga
Shota Imanaga is a 30-year-old left-handed pitcher from Japan. He most recently for Yokohama Bay Stars of the Nippon Professional Baseball League. Over the last 3 seasons, he has averaged 155 innings pitched, with an average of 25 starts in those 3 seasons. Imanaga has been a very reliable pitcher in Japan.
Imanaga is a little bit older for someone making the jump to the MLB but that hasn't stopped the Mariners from signing a player like Imanaga, the Mariners signed Hisashi Iwakuma when he was 31. In 2023 Imanaga had a 2.66 ERA, a 1.019 WHIP, 188 Ks, and 24 walks. I think Imanaga could be a fit if the Mariners do end up trading one of their young pitchers and don't want to fork out the money for Blake Snell.
MLB Trade Rumors predicts Imanaga to get a 5 year $85 million deal.