The 3 best and 2 worst developments of Mariners' 2025 spring training

The Seattle Mariners put the spring training portion of their 2025 season to bed on Monday, and they did so with a final record of 11-19 in Cactus League play. That tied for the worst in all of MLB.

A bad omen? Eh, probably not. Though finishing with the worst record for any given spring isn't a good omen, per se, there historically isn't much in the way of correlation between how teams perform in practice games and how they perform in real ones.

This inevitably brings us to the question of what aspects of the Mariners' experience in the 2025 Cactus League do matter? Or, more specifically, what went right and what went wrong?

Let's get into it by looking at the three best and two worst developments for the Mariners this spring.

Best: J-Rod and Big Dumper in midseason form

Though it isn't uncommon for teams to let their big stars take it easy during the spring, the Mariners took the opposite approach with Julio Rodríguez and Cal Raleigh. They played in a total of 37 games and, yeah, it's fair to say they made the most of them.

Rodríguez and Raleigh each hit five home runs and combined to drive in 30 runs. Two-thirds of those RBIs landed on J-Rod's line, which is basically a way of saying he hit multiple grand slams without actually saying he hit multiple grand slams.

Amid an 85-77 season in 2024, the Mariners got 54 home runs and 9.3 fWAR from Rodríguez and Raleigh. Not a bad result by any stretch, but there's the potential for more to be mined from this duo. We know J-Rod has 30-30 upside and Raleigh may well have a 40-homer season in him.

If spring training is any indication — and, boy, is that "if" doing some heavy lifting — then 2025 may be the year that Rodríguez and Raleigh explode simultaneously.

Worst: Some shine came off the rotation

As teams across MLB struggled to maintain effective starting rotations in 2024, Mariners starters put on a show akin to Mike Tyson at a wet paper bag museum. They led the league in...oh, heck. You know the deal. Everything. They led the league in everything.

They may well do so again in 2025, but it could be after a rough start. George Kirby is going to be out until late April with inflammation in his right shoulder. Meanwhile, Logan Gilbert put up a 6.00 ERA during the spring, and Luis Castillo fanned only 11 batters in 18 innings.

Gilbert's ERA isn't really worth worrying about. But Castillo's Ks? Maybe. The 32-year-old took a step back with his strikeout rate in 2024, and his fastball velocity is trending the same way. He sat at 93.9 mph this spring, down from 96.3 mph just two years ago.

Best: What if the Mariners had a good offseason?

So, the Mariners' offseason. By all accounts, it was not a good one. And that may prove to be the case as the 2025 season plays out.

For now, though, bringing back Jorge Polanco on a one-year, $7.75 million deal looks like a potential stroke of genius. He had knee surgery during the offseason and it seems to have made a difference. He got into 13 games this spring and slugged .615, and otherwise seemed ready for his move from second base to third base.

Other newcomers who hit well during the spring include Donovan Solano, who did his "Donnie Barrels" thing by batting .314, and Miles Mastrobuoni, who batted .429.

The Mariners otherwise got an unexpected boost from non-roster invitee Rowdy Tellez, who's positioned to ride a .894 OPS for the spring to a spot on the Opening Day roster. He could be a key source of left-handed power, something that the Mariners would have been short on otherwise.

Worst: Happy trails, Mitch Haniger

Probably the most shocking story of the Mariners' spring happened right at the end, when they released Mitch Haniger this past Sunday. They did so with an understandably heavy heart.

“Mitch has been a significant part of Mariners history and will be missed,” Mariners president of baseball operations Jerry Dipoto said in a statement. “The day he arrived for his first Spring Training back in 2017, he established himself as one of the most focused, prepared, and hardest working players I’ve ever been around. We all appreciate the many ways he’s made us all better, on the field and off.”

Mind you, this fate wasn't necessarily undeserved on Haniger's part. The 2018 All-Star is 34 and he wasn't even a replacement-level player in 2023 and 2024. He also went just 3-for-18 this spring before having to take to the sidelines because of a sore left shoulder.

All the same, it's an unceremonious end for a fan favorite, and you have to wonder if the Mariners erred in not trying to move on from Haniger sooner. Trading him during the offseason would have been difficult, but any success in that endeavor would have been preferable to letting him go and eating his $15.5 million salary.

Best: They avoided catastrophe

Starting pitching issues and Haniger's release aside, this was a relatively drama-free spring training for the Mariners in Peoria.

Sure, the record was bad, but we've covered how that probably doesn't matter. And it is certainly that much easier to assume as much because of how the Mariners didn't lose all those games by way of injuries. As they prepare to head north to face the Athletics at T-Mobile Park on Thursday, Kirby's shoulder is the only real injury of note.

To this end, they sure did better than the Texas Rangers, who had to turn to Patrick Corbin in desperation after injuries to Jon Gray and Cody Bradford. The New York Yankees are another key American League rival that was bitten in half by the injury bug, with Gerrit Cole, Luis Gil, Giancarlo Stanton, and Clarke Schmidt all out of the picture for at least the opening weeks of the season.

All the Mariners have to do now, of course, is go play the games. The real ones, that is, and all 162 of them. Hopefully, they'll win more than they lose and they can make it back to the postseason for the first time since 2022.