Analysis: How Josh Naylor Trade Makes Mariners Much Better in 2025
It has begun.
The Seattle Mariners have kicked off the trade season with a bang, acquiring Josh Naylor from the Arizona Diamondbacks in exchange for left-handed pitching prospect Brandyn Garcia and right-hander Ashton Izzi.
Let’s start with what the Mariners are getting in Naylor, and do so by asking some easy questions.
What has Naylor done?
A little bit of everything. Naylor was a first-round pick in 2012 by the Marlins who is no stranger to being traded, as this is the fourth time he’s had to pack his bags. After some shaky seasons with San DIego, he put things together with the Guardians, and established himself as one of the better young first baseman in the sport. He forged an .843 OPS in 2023 over 495 plate appearances in 2023, and then followed that up with a 31-homer campaign in 2024. He was traded in the offseason for Slade Cecconi in a cost-cutting move from Cleveland to Arizona, and in his lone season with the D-backs, he was slashing .292/.360/.447 with 11 homers over 349 at-bats.
What does he do well?
A little bit of everything, again. Despite having a build that might suggest a grip-and-rip slugger, that’s not really Naylor’s game at all, He makes contact (more on that in a second) to all parts of the field, and his expected batting average of .288 shows that his current average is no fluke, and that former number ranks in the 90th percentile of all qualified hitters.
Naylor also recognizes pitches exceptionally well, and that leads to squaring up the baseball on a consistent basis (31.5 percent) and also makes him someone difficult to strike out. Naylor has only been punched out in 12.4 percent, and the reason that number is so impressive -- on top of it just being, well, impressive -- is that he’s more than willing to draw walks with a rate of 9.4 percent. He’s an excellent bad-ball hitter, and he’s not someone who has a clear weakness in his offensive skill set.
And despite his less-than-spectacular speed, Naylor has been able to procure more steals than you might expect. He’s up to 11 on the season, and he’s not someone known for making baserunning gaffes. So that’s nice.
What does he struggle with?
Not a little bit of everything, but it’s worth noting that this is not an elite power hitter, so the hit tool is going to have to play up. He barrels the baseball just 6.6 percent of the time with a hard-hit percentage just a tick above 40 percent, and both those figures leave a bit to be desired. That’s particularly concerning considering where he’ll be playing his home games, so fans should be pleasantly surprised if he’s a major source of power.
There’s also the platoon factor, or whether or not Naylor needs to be platooned. My personal opinion? No, but he’s much better against right-handers than he is versus southpaws. He’s someone you can hit in the middle of the order against righties, but it makes more sense to hit closer to the bottom than the top when facing same-sided hurlers.
And, there’s the defensive stuff. Naylor isn’t abhorrent with the glove, but isn’t going to remind anyone of Evan White or John Olerud or David Segui.
These are more nitpicks than criticisms, but there are certainly flaws in Naylor’s game.
What did the Mariners give up?
Mariner fans saw Garcia pitch in the series against the Brewers, and saw why there’s some reason to be excited, and some reason to believe that he’s going to need a lot of work to reach his ceiling. The stuff is unquestionably good enough to be a starter. The command needs an awful lot of work. There’s a ton of potential outcomes for Garcia, and Arizona should give him a chance to start. I’m not sure he can.
Izzi is more interesting, at least in terms of the potential to be in a rotation. He’s a 2022 fourth-round pick who has a plus fastball and an above-average slider, but like Garcia, there are significant command issues and he’s never thrown more than 110 2/3 innings in his time as a professional. If everything clicks, he’s a mid-rotation starter. If it doesn’t, he’s organizational depth.
I’m not saying this is a bad return for Naylor, a player who is going to be a free agent at the end of the year for a team that is no longer in playoff contention. But it’s a really easy trade to make if you’re Seattle. None of those players would rank inside of my Top 15 prospects, and Seattle has players of similar talent that make these type of prospects "replaceable." Not bad for Arizona, but an easy yes for Seattle, in my humble estimation.
Where would you hit Naylor?
This probably won’t be what Seattle does, but I’d have Naylor hit third against right-handers and seventh against lefties. I like the idea of Naylor hitting right after J.P. Crawford and Julio Rodriguez, and behind the bashers of Cal Raleigh and Randy Arozarena. Against lefties I don't want him getting as many plate appearances, but he’s just good enough there -- and better than Donovan Solano -- to be in the lineup.
Is this enough?
No. And the Mariners know that. They have massively upgraded the first base position -- and again, without giving up their top prospects -- and added ceiling and floor to the lineup. But it’s not enough. They need another bat, they need another reliever, and I think they need another starter. And by the way, this deal doesn’t stop them from getting Eugenio Suarez at all. Those were always likely to be separate transactions.
This is a great start. But it’s just that. A start. Go finish it.
