Trade Deadline Outlook: Seattle Mariners

The Mariners are coming off an ALCS appearance in 2025 and are looking to go even farther in 2026. They are in decent position thus far, as they have a slight lead in a tight American League West. A lot of the roster is in good position, so they might only look to make marginal additions, though they have a strong farm system and could make a bold strike if they wanted to.

Record: 47-46 (82.7% playoff probability, per FanGraphs)

Buy Mode

Potential needs: right-handed bat, relief pitching, ace

Despite a fairly middling record, the Seattle roster looks quite strong on paper. The rotation is six deep, forcing the club to awkwardly jam their starters into unusual piggybacking scenarios. The bullpen is also putting up good numbers. As a whole, the pitching staff has a 3.54 earned run average. Only the Brewers, Yankees and Dodgers are better in that category. Seattle could and should pick up another reliever or two. Even clubs with good bullpens can squeeze an extra guy in there to bump out the weakest link. The Mariners are one of the few clubs who don’t need to be looking for rotation help. That doesn’t mean they couldn’t, however. More on that below.

The lineup is more middling. They have a collective .230/.311/.379 line, which leads to a 101 wRC+, a hair above average and 15th in the majors. Among the lineup regulars, few are truly flourishing but few are really obvious candidates to be replaced. At last year’s deadline, the Mariners added two big bats when they traded for Josh Naylor and Eugenio Suárez. Doing the same this year might be a bit harder to pull off.

Nine different Mariners have made at least 130 plate appearances this year. Most of those have been close to league average. Six of those nine have a wRC+ between 94 and 115. Randy Arozarena and Dominic Canzone are the two guys well above that window. That leaves one player way below, which is shockingly Cal Raleigh.