In Josh Naylor, Mariners acquire slugger they’ve been missing: grades, analysis

The Seattle Mariners acquired first baseman Josh Naylor from the Arizona Diamondbacks on Thursday, addressing their need for a corner infield slugger to complement catcher Cal Raleigh. Seattle had been expected to target help at first or third base due to limited production from players like Rowdy Tellez and Donovan Solano.

For the Diamondbacks, this trade represents the start of a potential sell-off. Despite lingering on the fringe of playoff contention, their odds are low (10.8%), and they possess several pending free agents like Eugenio Suárez, Zac Gallen, and Merrill Kelly, positioning them to potentially benefit significantly if they fully commit to selling at the deadline.

In exchange for Naylor, the Mariners sent prospect left-hander Brandyn Garcia (their No. 11 prospect) and right-hander Ashton Izzi (No. 19 prospect pre-season) to Arizona. Garcia recently made his MLB debut after converting to relief, while Izzi, 21, has struggled with control in Class-A and may project as a reliever.

Naylor, a 28-year-old left-handed hitter, entered Thursday slashing .292/.360/.447 with 11 home runs, 59 RBI, and a 124 OPS+, contributing 1.0 bWAR. Acquired by Arizona from Cleveland last December, he is in his final year before free agency. While he hit a career-high 31 homers in 2023, his 2024 performance resembles a healthier version of his 2023 form with better average and on-base skills, a low strikeout rate, but more modest power.

Mariners President Jerry Dipoto sought to fix clear infield corner deficiencies. Naylor provides an offensive upgrade at first base (123 wRC+ vs. Luke Raley's 108 wRC+), lengthening the lineup primarily through his on-base ability. However, his power might decrease moving from hitter-friendly Chase Field to pitcher-friendly T-Mobile Park.

Diamondbacks GM Mike Hazen, facing uncertainty about how much to sell, initiated this move following a sweep by Houston. The return for rental player Naylor appears light, potentially reflecting the market rate. With over a week until the deadline, Hazen still needs to maximize returns for players like Suárez and decide on starters Gallen or Kelly. He may remain in contact with Dipoto, as Seattle still needs a third baseman.

The trade, involving frequent partners Dipoto and Hazen, gives Seattle a left-handed power bat (ranked 17th on The Athletic's trade board) to pair with Raleigh.