Mariners Spring Training Update: Kade Anderson debut, Luis Castillo velo, injury news

The Seattle Mariners are now less than four weeks from opening their season on March 26, and it's only getting harder to keep track of what's happening in Peoria.

For anyone who isn't scoring at home, the M's are only 3-5 in Cactus League play after a little over a week's worth of games. The pitching has had a rough go of things, as only two clubs have allowed more runs than Seattle's 62.

But on a scale of 1-10, how the team is performing in the Cactus League is at best a 2 in terms of importance. There are bigger storylines in play, starting with the pro debut of one of the organization's top prospects on Saturday.

Mariners Spring Training Update: Kade Anderson punches out the side in his first professional inning

After sitting out the remainder of the 2025 minor league season after going No. 3 in the draft, Kade Anderson finally toed the slab for the Mariners in an official capacity on Saturday. He got the start against the San Diego Padres, and made an impression by striking out the side in the first inning.

The 21-year-old also battled some adversity in that first inning, as he had to work around an infield single and a walk. He didn't get an out in the second inning, as Dan Wilson lifted him after a 102.3 mph single by Freddy Fermin and a 105.3 mph double by Jake Cronenworth. He was ultimately charged with two runs when they came around to score.

The lefty threw 30 pitches, with an average of 93.8 mph and a peak of 94.9 mph on the fastball. While that isn't impressive velocity, his 17 inches of vertical break and five inches or horizontal break highlight his fastball's impressive shape. He also got three whiffs on three swings against his changeup.

Now it's Ryan Sloan's turn, as the righty is slated to pitch in Sunday's exhibition against the Rangers. Anderson and Sloan rank as MLB Pipeline's No. 21 and No. 33 prospects, respectively.

Mariners Spring Training Update: Luis Castillo is ahead of schedule with his velocity

Luis Castillo, meanwhile, got hit around a bit in his Cactus League debut on Friday. He faced the Arizona Diamondbacks and gave up three runs on four hits while recording four outs.

Castillo did, however, sit at 95.0 mph with a high of 96.3 mph with his fastball. That's quite the difference from last spring, when he didn't even crack 94 mph with his average fastball.

The 33-year-old ended up averaging 95.0 mph on his four-seamer during the regular season in 2025, so the fact that he's already there is encouraging. It's also by design, as Castillo has alluded to having spent the offseason trying to increase his velocity.

If Castillo can gain back some of the velo he's lost in recent seasons, that can only help him stave off what has been an ongoing decline. He's lost 2.1 mph on his average fastball since 2022, and his strikeout rate fell to a career-low 8.1 per nine innings in 2025.

Mariners Spring Training Update: Injury news on Bryce Miller, J.P. Crawford, Victor Labrada

There is unfortunately no such thing as a spring training without bad injury news, and the Mariners got some on Saturday.

According to Daniel Kramer of MLB.com, Bryce Miller has inflammation in his left oblique that's going to cost him his next Cactus League start. He had impressed in his debut on Thursday, after which his vibes were off the charts.

Also experiencing oblique trouble is outfield prospect Victor Labrada, who strained one of his while working in a batting cage. Per Kramer, Mariners GM Justin Hollander expects Labrada to be sidelined for a "more extended period." It's a tough break for the 26-year-old, who had been ranked as the team's No. 27 prospect last season, with a major league ETA of 2026.

As for the sore right shoulder that has kept J.P. Crawford sidelined, he's making progress and is set to return to the lineup at designated hitter on Tuesday. If all continues to go well, he could return to shortstop by March 8.

In other words, enjoy Colt Emerson at shortstop while you can. Once Crawford is back at short, Emerson will have to make an impression playing out of position at third base and second base.