Bumpy Stretch For Rotation Blocking Mariners’ Breakthrough

One of the clear strengths of the Seattle Mariners at the beginning of the 2026 season was their starting rotation. Last season, they ranked fourth in Major League Baseball in innings pitched as a starting rotation and 11th in FIP (which is ERA but factoring out fielding luck).

Bryan Woo and Luis Castillo eclipsed 180 innings pitched. Two of their starters had an ERA better than 3.50. Three of them exceeded 160 strikeouts. Four of their starters made at least 23 starts last season. Eight different players needed to make at least two starts. For context, the World Series champion Dodgers had 14 different players make multiple starts. The American League champion Blue Jays needed 11 such starters.

They had one of the strongest, most reliable rotations in baseball last year. With the same cast of characters coming into 2026, the consensus was the Mariners would be able to lean on their starting pitchers to another postseason run. However, over the last few weeks, the starting pitching has not been the strength, but the weakness of this Mariners club.