Kade Anderson’s first big-league start had the kind of opening that can fool you into thinking the night will belong entirely to the rookie. For four innings, the Mariners’ left-hander was in control, working cleanly through the Cubs before the game tilted in the sixth.
Anderson, MLB Pipeline’s No. 5 overall prospect for 2026, finished his MLB debut with three runs allowed over 5 2/3 innings in Seattle’s 5-4 win on Saturday. He gave up five hits and two walks while striking out five, and the Mariners still walked it off on Randy Arozarena’s two-run homer.
The trouble arrived late. Anderson was one out from getting through six innings when the Cubs finally broke through in the fifth on a sacrifice fly. In the sixth, Alex Bregman and Michael Busch went back-to-back with solo homers, and Anderson’s night ended to a standing ovation from the Seattle crowd.
The final line looked rougher than the first four frames suggested, but the bigger question may have been how long Seattle let him stay out there. The Seattle Times’ Adam Jude noted that Anderson’s high-water mark for pitches in the minors this year was 80, back in June. He entered the sixth at 72 pitches and then surrendered those two home runs on pitches 80 and 81.
Even so, the Mariners had plenty to like. Anderson faced the club sitting atop the National League Wild Card race and held them in check for most of the afternoon. He also did it with just 18 Double-A games behind him before his first major league start.
It would be a surprise if Seattle sent him back down after one outing, so another big-league start next week seems likely. The real test now is how the Mariners manage his workload from here, especially after the Cubs did most of their damage on the final pitches of his debut.
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