First spring all about learning and growing for No. 2 prospect Anderson

8:26 PM UTC

PEORIA, Ariz. -- For , Friday night was about the finish.

The Mariners’ wunderkind left-hander made what wound up being his final start of an impressive Cactus League slate, covering three innings in a 10-7 loss to the Dodgers and working through a mid-game adjustment that helped salvage the outing.

On Saturday afternoon, he was reassigned to Minor League camp.

“It's been a lot of fun,” Anderson said. “I've learned a lot, and it's been nice to kind of get to know everyone. So when that day does come, it's going to be smooth sailing.”

Anderson made three Cactus starts, over which he surrendered five earned runs in seven innings (6.43 ERA), with nine strikeouts and three walks. He was stretched out to 51 pitches in his final outing, and shouldered a workload akin to the rest of Seattle’s starting staff.

The next steps to his player development plan will likely include an assignment at Double-A Arkansas, which itself represents a big first step -- given that the Cactus slate was his first showing in pro ball altogether.

The Mariners have typically sent their more seasoned pitching prospects there over Triple-A Tacoma, at least early in the season, because the weather is less volatile than at Triple-A Tacoma. Anderson, who was selected with the No. 3 overall pick in last July’s MLB Draft, is Seattle’s No. 2 prospect and MLB Pipeline’s No. 21 overall.

On Friday, Anderson was sporadic in the first inning and ambushed for a three-run homer from Teoscar Hernández.

A dugout conversation with pitching coach Pete Woodworth helped steer him back on course.

"When you have a tough inning, you need to help the bullpen out and get as many innings as you can,” Anderson said. "And you're not going to have your stuff every day. So it's part of the game. The mentality standpoint, it's half the battle, so I'm really just trying to work on that.”

These are the growing points that the Mariners want to see in any young pitcher, especially one who was deliberate about bullpen usage for an inconsequential game in which there was an army of just-in-case arms available if needed.

But these moments are especially telling for one who is just nine months removed from college ball -- and more chiefly, who could potentially help them in the Majors in 2026.

"Whether or not it's in '26, I don't know,” Mariners manager Dan Wilson said. “But to know that we have a pretty special competitor out there, and someone who can throw the ball, throw it well, and have a great poise on the mound with it, that's exciting. And to know he's going to get started professionally this year is also exciting. It'll be interesting to follow his progress as he goes.”

After the homer, Anderson went on to retire eight of his final 10 batters. He ended his day via a called strikeout to Alex Call in the third inning on a fastball that dotted the outer half, which followed a nifty double play from new third baseman Brendan Donovan that eliminated Anderson’s leadoff walk.

The homer surrendered to Hernández (a player who’s crushed at least 25 in each of the past five seasons) was set up by another walk (to mega free-agent signing Kyle Tucker) and a leadoff double (to 2025 World Series hero Miguel Rojas). It was probably the most seasoned stretch of hitters that Anderson has ever faced.

He finished with four strikeouts, two walks and three hits, throwing 51 pitches (32 strikes).

"It's nice to know that my stuff still plays at this level,” Anderson said. “I didn't know that until, obviously, I got here, so that's nice. And really, just from a mentality standpoint, I learned a lot from today, just being able to go out there and fight. I didn't have my best stuff today, but like I said, keeping the team in the ballgame is really just what I'm supposed to do.”

On Friday, he was pitching on a seven-day routine after going through a six-day routine through the first weeks of Cactus League play. If he remains on that schedule, it’d line him up to pitch in next Friday’s Spring Breakout, which would make sense given how high of a priority the prospect showcase has become.

And now that this was indeed it among his big league peers -- at least for now -- how does he assess his first camp?

"Obviously some good, some bad, and some just average,” Anderson said. “But I thought, really, just trying to get my feet wet, trying to learn from the guys, experience everything I can. This isn't the big leagues, but it's as close as it's going to get. So you try to take everything with it and just try to dive all in."