Coming into the year as one of the deepest rotations in baseball, the Seattle Mariners were expected to build their success in the pitching department in 2026. They came out of the gate strong, performing as one of the best units in the league over the first couple of weeks. While they have come back to the pack slightly since then, the Mariners’ starters have remained one of the most consistent rotations in baseball, ranking third in quality starts.<\/p>\n
With Bryce Miller<\/a> returning from injury and Kade Anderson<\/a> emerging as one of the top pitching prospects in the game, difficult decisions may soon face the front office. With each starter now through six outings, it\u2019s time to assess and rank the rotation based on their performance so far in 2026.<\/p>\n These rankings of the Mariners starters are based on performance, consistency, and overall impact through the first six starts.<\/p>\n Following an impressive first start against the New York Yankees, Luis Castillo<\/a> has struggled mightily in subsequent outings, conceding seven runs in two of his five starts and four runs in two more. As a result, even with a six-inning, scoreless outing, his ERA in 2026 sits at 6.35, with a WHIP of 1.73.<\/p>\n He has not been able to locate his pitches, and the arsenal that has been so consistent since joining Seattle in 2022 has not only been picked apart but hit hard across the park. Following five innings in Minnesota, where he gave up seven runs, his spot in the rotation has come under scrutiny, with Miller expected back sooner rather than later.<\/p>\n Castillo has gone through rough stretches during his time in Seattle, including as recently as August last season, when he struggled for several consecutive outings before returning to form. He does have the protection of a large contract, which will make any front office decision difficult to navigate. However, Castillo will need to return to form soon, or the pressure will only increase.<\/p>\n Perhaps a victim of expectations, Logan Gilbert<\/a>, viewed internally as the ace of one of the best rotations in baseball, as shown by his Opening Day nod<\/a>, has had a disappointing start to the 2026 season. In a vacuum, his performances have been fine, but for someone seeking a long-term contract, he has been subpar. More concerningly, the issues he showed in 2025 have carried over into 2026 and are beginning to hurt his overall effectiveness.<\/p>\n His stuff will always rank among the best in the league. Gilbert\u2019s splitter remains one of the best individual pitches in baseball, and his strikeouts per nine innings still lead the Seattle staff at 9.93, with the rest of the rotation sitting in the 7\u20138 range. However, he has struggled to get out of innings efficiently. His pitch count climbs early in games, and he has found it difficult to work deep into starts, reaching six innings only twice in his first six outings. He attempted to counter this by adding a cutter and sinker<\/a> in the offseason, but those pitches have not performed as hoped.<\/p>\n Logan Gilbert is rocking a career low in HR\/9 & HR\/FB<\/p>\n Byron Buxton clearly did not get the memo as he leaves the yard for the 7th time in 13 games pic.twitter.com\/9qAjSOGCPu<\/a><\/p>\n \u2014 Baseball Unstitched (@BaseUnstitched) April 29, 2026<\/a><\/p><\/blockquote>\nRanking the Mariners Starters Through Six Games Apiece<\/h2>\n
5. Luis Castillo<\/h3>\n
4. Logan Gilbert<\/h3>\n
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