Hot-hitting Dom Canzone has swung his way into Mariners’ full-time lineup

You can cross the platoon label off Dom Canzone’s hitting profile. The Mariners’ designated hitter has swung his way into a full-time, middle-of-the-lineup role, regardless of the handedness of the opposing pitcher.

“He’s earned it,” club president Jerry Dipoto said.

A 28-year-old left-handed hitter, Canzone was almost immediately tagged with a can’t-hit-lefties label after he arrived in Seattle as part of the return from Arizona in the trade for closer Paul Sewald in July 2023.

He had 27 plate appearances vs. left-handed pitchers in 2023 and just 14 during an injury-riddled 2024.

He had a larger breakthrough in the second half of 2025, hitting .300 with 11 homers, a .840 OPS and a 141 wRC+ (100 is average) in 82 games. Much of that success came against right-handed pitching, but there was a notable uptick against lefties (albeit in a small sample size of 68 plate appearances).

That’s carried over into this season, and Canzone now ranks not only as one of the Mariners’ best individual stories but also as one of the 10 best sluggers in baseball, according to advanced metrics.

Canzone has a 155 wRC+ that ranks No. 6 in MLB and his 10.8% barrel rate also ranks No. 6.

“Dom, for the last calendar year, has been about as good as any left-handed hitter in the league, and better than almost all of them when matched up versus righties,” Dipoto said. “He’s always been capable versus lefties, but never really had a lot of runway with opportunity. We gave him some last year, and this year he just got into such a good groove and a hot spell, and we were so banged up that it gave him a few extra reps against lefties, and he did something with it.”

Overall, Canzone has a .273/.349/.551 slash line in 232 plate appearances this season. His .900 OPS leads the team and he is tied with Julio Rodríguez and Luke Raley for the team lead with 14 homers.

Canzone continues to mash righties, hitting 12 of his 14 homers against them and slugging .552 with an .887 OPS in 203 plate appearances.

What’s most intriguing, though, is his .545 slugging and .994 OPS against left-handed pitching this season. That’s, again, in a limited sample size (29 plate appearances), but it’s certainly enough to warrant an everyday spot in the lineup, particularly for a club that has struggled offensively the past few weeks.

Canzone did make a recent adjustment to his setup against left-handed pitchers, in which he opens up his front side, allowing both of his eyes to be more square to the pitcher. This, he said, allows him to pick up spin a little bit quicker, and he feels he’s less inclined to chase sliders off the plate.

It’s a setup he began to use after a conversation with teammate J.P. Crawford, who has long had an open stance.

“That’s been nice,” Canzone said. “I really look for something a little bit closer and not try to cover everything (on the outer edge of the plate), so that I think that’s been a little bit of a help for sure.”

Canzone also had a recent conversation with manager Dan Wilson about getting more chances vs. lefties.

“If the opportunity were to come to,” Canzone said, paraphrasing the conversation, “maybe the first five or 10 at-bats off lefties might not be the greatest, right? So just trying to stick with it and not abandon ship right away. And that’s definitely comforting, knowing it’s OK to fail and you’re going to get your opportunities.”

Early in his first full season in Seattle, Canzone sprained the AC joint in his left shoulder while crashing into the left-field wall to make a catch. He spent a month on the injured list, but said he never quite felt 100% the rest of that season.

“Trying to play through that was really difficult,” he said. “So it’s been a combination of things. Just getting healthy, learning from how guys are pitching you, understanding situations. With anything, the more opportunity you get, the more you practice in, the more reps you get, the better off you’re going to be.

Last season, with guidance from Edgar Martinez and new hitting coaches Kevin Seitzer and Bobby Magallanes, Canzone stopped trying to pull everything off the right-field foul pole. He embraced an up-the-middle approach that clicked.

“He couldn’t hit a ball the other way to save his life,” Seitzer said.

Canzone’s mindset now is to hit fastballs on a line up the middle. Simple as it gets.

“When he got on this roll, it was just (about) trying not to do too much, shorten up (the swing), use your hands, and stay in the middle of the field,” Seitzer said. “And then all of a sudden barrels started coming. He’s been in a really good place.”

Like most MLB clubs that lean into data-driven strategies, the Mariners have employed platoon roles at one or two spots in the lineup in recent years. Many would point to platoons as one of the key factors in the success of small-market teams like the Brewers and Rays, and there is sound reasoning behind it.

Across MLB this season, left-handed hitters have a .235 batting average, a .676 OPS and a 89 wRC+ against left-handed pitchers. Against right-handed pitchers, left-handed hitters have a .246 average, a .727 OPS and a 101 wRC+.

Canzone, limited the past two weeks by a minor hamstring strain, has taken the plate appearances against lefties that the Mariners were giving early in the season to Rob Refsnyder, the veteran right-handed half of the platoon. Refsnyder has struggled in his first season in Seattle, and he’s currently on the IL with knee inflammation.

The Mariners are expected to continued with their platoon in right field with Raley and Victor Robles. Raley has a career .788 OPS against right-handed pitching and a .511 OPS vs. lefties.