Mason Peters shines in short AquaSox debut

Published 4:20 pm Thursday, August 13, 2026

EVERETT — Mason Peters knew exactly what he wanted to do when he took the mound against the Spokane Indians at Everett Memorial Stadium on Thursday, his first time for the Everett AquaSox.

“Last night and this morning, I just made the dedication that I was going to attack the zone and get ahead in counts,” Peters said. “Win the 1-1 (counts), finish. That was my goal regardless of the outcome, regardless of the hits or anything like that.”

The 22-year-old lefty started out using more of his fastball, which sat around 93 mph, and drew a lot of contact while starting ahead 0-1 on two of the four at-bats in the first inning. It was an efficient start, but it wasn’t until he started mixing in his off speed pitches that he really showed why the Seattle Mariners promoted him from Single-A Inland Empire on Monday.

With six strikeouts over the next two innings, Peters mowed down the Spokane lineup. He allowed just one hit and one walk in 3 1/3 shutout innings, throwing just 48 pitches before the bullpen took over and powered Everett (57-54 overall, 24-21 second-half) to a 7-1 victory over the Indians (50-60, 21-23).

“It’s always good to have a left-handed starter,” AquaSox manager Ryan Scott said. “Those are always good to kind of throw it off. We’ve been going right-handed starters for a while now, so it’s good to bring him in the mix. He’s earned the promotion, so we’re really excited to get him up here, and really just excited to see him go do more of what he did tonight, which is go out there, dominate the zone, get some weak contact, punch some guys out, and really fill that thing up and use his best stuff over the plate.”

The Mariners selected Peters in the fourth round of the 2025 MLB Draft out of Dallas Baptist University, and he posted a 1.43 ERA across 14 starts with Inland Empire this season. After allowing three earned runs in his professional debut, Peters did not allow more than one run in any of his subsequent starts. He notched 68 strikeouts while walking just 12 in 50 1/3 innings with Inland Empire, posting 12.2 strikeouts per nine innings (K/9) and a 5.67 strikeout-to-walk rate (K/BB). His 0.85 WHIP and .175 batting average against displayed he had little left to prove in Single-A.

“It’s his first year, but he’s a pro,” Everett pitching coach Bryan Pall said. “He takes care of his business. He knows what his plan is. He came prepared to our meeting, and that was great, and we executed that plan.”

Pall emphasized the importance of communicating between coaching staffs when it comes to bringing in promoted players, and that was no different with Peters, whose biggest focus is developing his routine in his first season as a full-time starter. Peters made just four starts in 20 total appearances with Dallas Baptist last season, but the Mariners organization believes he has the arsenal to handle a starter’s workload, according to Pall. Peters said building up that workload has been the biggest challenge so far.

“Just throwing a full (bullpen session) and a full start pitching deep into games,” said Peters, who is Seattle’s No. 13-ranked prospect on MLB Pipeline. “Especially as I want to chase strikeouts, I want to eliminate walks, so you’re trying to do all these things and meet all these goals, but also be efficient. So it’s juggling that for sure, but trying to pitch as deep into games as I can.”

The Waco, Texas native has made it past four innings in a start just twice this season as he works to build up his stamina, but the organization is taking a patient approach. Peters missed a six-week stretch from mid-June to late July due to forearm soreness, which is another reason why the coaching staff does not want to overwork him.

“It’s his first full season, we’re kind of tailing down just to protect him,” Pall said. “Don’t want to rush into anything. He’s had a fantastic year, don’t want to push it too hard.”

When Peters finally took the mound on Thursday, he got into the action early. He fielded a grounder from Spokane infielder Kevin Hidalgo and whipped around for a quick put out at first to pick up his second out of the afternoon. Infielder Ethan Hedges picked up the lone hit on a single to left field, but Peters got infielder Wilder Dalis to ground out and end the inning.

Each of the first four AquaSox batters reached base in the bottom of the first, as outfielder Aiden Taurek and infielder Brandon Eike hit back-to-back RBI base hits to give Everett a 2-0 lead. Taurek got tagged advancing to second after driving in outfielder Korbyn Dickerson, but Eike still scored catcher Luke Stevenson from third with a double to right field.

Peters opened the second with his first strikeout, and nearly rung up outfielder Robert Calaz on a full count, but home plate umpire Ricardo Capois called a ball to make it a walk. Peters turned around and struck out the next two batters to end the frame, getting designated hitter Jacob Hinderleider to whiff after working back from a 2-0 count before punching out outfielder Derek Bernard.

“In the second inning, I started to spin a little bit more, and (I) know that that’s my strong suit,” Peters said. “So I got in some advantage counts and was able to put some guys away.”

Peters would have struck out the side in the third, but Hidalgo reached on a dropped third strike to keep the inning alive. Once again, Peters made it inconsequential by getting Hedges to ground into a fielder’s choice to end the inning.

Taurek and Eike worked back-to-back walks in the bottom of the third, which set up designated hitter Ricardo Cova for an RBI double to center to make it 3-0, but infielder Austin St. Laurent and outfielder Cesar Quintas failed to plate the two runners left in scoring position. Peters picked up one more out in the top of the fourth before Ben Hernandez came in to replace him.

Dickerson pushed the AquaSox lead to 5-0 in the bottom of the fourth with a two-run homer to right field, and Hernandez faced the minimum in the fifth after inducing a double play from catcher Juan Castillo, but Spokane got on the board in the sixth with an RBI single from infielder Tanner Thach off reliever Sam Whiting.

“(Dickerson) is always going to put together good at-bats,” Scott said. “… The more we can see him start to shrink his zone a little bit and get balls over the middle of the plate, let his bat work and go do what he does best, it’s going to be really good for him.”

Whiting returned to pitch a quick seventh inning, and Wyatt Lunsford-Shenkman stranded two Spokane batters in the eighth before St. Laurent padded the lead to 7-1 with a two-run double in the bottom of the frame. Lunsford-Shenkman returned for the ninth, pitching a 1-2-3 frame to cap off a dominant outing from the pitching staff.

After three straight wins against the Indians, Everett will look to extend the streak on Friday at 7:05 p.m. PT.