Mariners' Top Prospect Kade Anderson Tosses Best Start Yet in Majors

The 2025 first-rounder was called up last month

Sep 9, 2026; Seattle, Washington, USA; Seattle Mariners starting pitcher Kade Anderson (13) pitches to the Texas Rangers in the first inning at T-Mobile Park. Mandatory Credit: Richard Dizon-Imagn Images | IMAGN IMAGES via Reuters Connect

The Seattle Mariners' No. 1 prospect, left-handed pitcher Kade Anderson, has officially earned his first MLB win.

Anderson, MLB Pipeline's No. 5 overall prospect for 2026, threw six strong innings for the Mariners on Wednesday. The 22-year-old allowed just one run on six hits and one walk while striking out five in Seattle's 3-2 victory over the Texas Rangers. Texas' only run against the southpaw came on a solo shot by first baseman Jake Burger in the second inning.

With Wednesday's outing, Anderson earned his first quality start in the majors. The left-hander has made just four starts since being called up to Seattle last month, but this performance marked his first time completing six innings, allowing only one run, and walking just one batter in the big leagues. His five strikeouts also tied his early MLB career high, a mark he's sure to surpass eventually.

Kade Anderson most likely only has a few starts left in 2026

Aug 29, 2026; Toronto, Ontario, CAN; Seattle Mariners pitcher Kade Anderson (13) pitches to the Toronto Blue Jays during the first inning at Rogers Centre. Mandatory Credit: Kevin Sousa-Imagn Images | IMAGN IMAGES via Reuters Connect

So far in 2026, Anderson has quickly shown why he's one of baseball's top pitching prospects. The No. 3 overall pick in the 2025 MLB Draft out of LSU made his professional debut this year, jumping right to Double-A. The young lefty made just 18 starts for the Double-A Arkansas Travelers before being promoted to the majors, posting a ridiculous 1.06 ERA and racking up 135 strikeouts in 93 1/3 innings.

In four MLB starts, Anderson now has a 4.29 ERA with 16 strikeouts in 21 innings. The southpaw has allowed 10 earned runs in the majors compared to 11 all season in the minors. He's also already walked eight hitters in the big leagues, despite issuing just 13 free passes in Double-A this year. But it's important to remember that the 6-foot-2 lefty is just 22 years old, and this is the first season of his pro career.

The Mariners are now 68-78 this season, 5.5 games back of the American League's third and final Wild Card spot. But with the season quickly coming to a close, Anderson will most likely make just a few more starts in 2026. Regardless, the young hurler will undoubtedly look to build on his latest outing and put the finishing touches on a strong first year in the Seattle organization.