The Seattle Mariners Have Acquired 1B Josh Naylor from the Diamondbacks!

The Seattle Mariners have officially made their first major move of the 2025 MLB trade deadline, acquiring veteran first baseman Josh Naylor from the Arizona Diamondbacks. This trade signals the Mariners’ serious intent to bolster their lineup and make a deep postseason run this year. In exchange, Seattle is sending two of its pitching prospects—left-handed pitcher Brandon Garcia and right-handed pitching prospect Ashton Izzy—to Arizona.

This article breaks down the details of the deal, why the Mariners made this move, the profiles of the players involved, and what this means for both teams moving forward. Let’s dive into what makes this trade significant and how it fits into Seattle’s strategy for the remainder of the season.

Why the Mariners Pulled the Trigger on Josh Naylor

Seattle has been searching for a consistent, left-handed bat to anchor their middle-of-the-order, and Josh Naylor fits that need perfectly. Naylor is a proven hitter with a solid track record of offensive production and plate discipline. So far this season, he has been an All-Star caliber player, boasting a .292 batting average, a .360 on-base percentage, and a .447 slugging percentage, giving him an 0.807 OPS and a 124 OPS+ (meaning he is 24% better than the league average hitter).

From a more advanced metrics standpoint, Naylor’s weighted runs created plus (wRC+) is 123 this year, indicating he creates 23% more runs than an average player. His ability to put together quality at-bats and make consistent contact is reflected in his 90th percentile expected batting average (.288) and 89th percentile squared-up rate. Additionally, his strikeout rate is in the 92nd percentile, meaning he strikes out less frequently than most players, which is a huge asset in today’s strikeout-heavy game.

For the Mariners, who have been juggling various players at first base this season—including Rowdy Tellez, outfielder Luke who has been filling in, and Donovan Solano—adding a natural first baseman like Naylor brings stability and a potent bat to the lineup. He is expected to slot in as an everyday player, providing left-handed power and plate discipline to complement stars like Julio Rodríguez, JP Crawford, Cal Raleigh, and Randy Arozarena.

Josh Naylor’s Career and 2025 Season Overview

Naylor has shown the ability to adjust his approach depending on team needs. Last year, he focused more on power, hitting 31 home runs and driving in 108 RBIs, although his batting average dipped to .243. This season, he has balanced power with contact, maintaining a strong batting average while still contributing 11 home runs and 11 stolen bases.

His splits this year highlight his strength against right-handed pitching, where he hits .310 with a .390 on-base percentage and a .493 slugging percentage, resulting in an .884 OPS. Against lefties, his numbers dip to a .258 average and a .655 OPS, but he remains a valuable asset in the lineup regardless of the pitcher.

Contract-wise, Naylor signed a $10.9 million arbitration deal with the Diamondbacks for this season. He will become a free agent after the year, so the Mariners are acquiring him for the stretch run in what could be a critical season for their playoff hopes.

The Prospects Heading to Arizona: Brandon Garcia and Ashton Izzy

In exchange for Naylor, Seattle is sending two pitching prospects to Arizona: Brandon Garcia and Ashton Izzy. Both are ranked within the Mariners’ top 20 prospects but represent relatively low capital compared to the value Naylor brings to Seattle’s lineup.

Brandon Garcia: Seattle’s Left-Handed Power Arm

Brandon Garcia is Seattle’s number 13 overall prospect, a left-handed pitcher drafted in the 11th round of the 2023 MLB draft out of Texas A&M. Garcia impressed last season as a starter in High-A Everett and Double-A Arkansas, logging 27 appearances (25 starts) with a 2.25 ERA, a 1.216 WHIP, and a strong strikeout rate of 10.4 per nine innings.

This season, the Mariners transitioned Garcia to the bullpen to fill a left-handed relief role alongside Gabe Speier. He throws hard, sitting 95-98 mph with a sinker and complements that with a gyro slider, a sweeping breaking ball, and a changeup. Garcia recently made his MLB debut, appearing twice out of the bullpen.

Arizona will likely view Garcia as a starter candidate, possibly transitioning him back to the rotation. Despite his solid stuff and potential, Seattle viewed Garcia as expendable given their bullpen depth and the immediate need for offensive help.

Ashton Izzy: A Flyer Right-Handed Starter

Ashton Izzy is the Mariners’ 16th ranked prospect and a 21-year-old right-handed starter currently pitching for the High-A Everett AquaSox. Drafted in the fourth round of the 2022 MLB draft, Izzy is still developing his skills and has yet to make a major impact in the minors.

This season, Izzy has struggled somewhat, posting a 5.51 ERA and a 1.563 WHIP over 47⅓ innings. However, he has maintained a solid strikeout rate of 10.3 per nine innings, showing potential as a strikeout pitcher. His control needs improvement, as reflected in his four walks per nine innings.

Given his performance and prospect status, Izzy is considered more of a flyer prospect in this deal, a low-risk asset that the Diamondbacks might be able to develop further.

What This Trade Means for the Mariners’ Lineup and Playoff Aspirations

The acquisition of Josh Naylor adds a crucial piece to Seattle’s lineup as they push toward the playoffs. By securing a natural first baseman with a strong left-handed bat, the Mariners can better balance their offensive attack and add depth to their middle order.

Seattle’s lineup already features explosive talents like Julio Rodríguez and Cal Raleigh, who is having an MVP-caliber season. Naylor’s presence gives the Mariners more options in crafting their batting order and presents a tougher challenge for opposing pitchers.

Moreover, Seattle’s front office appears to be aggressively pursuing additional upgrades. According to reports, the Mariners are still targeting Arizona’s third baseman Auhaneo Suarez, who is having an outstanding season with 36 home runs and is on pace for nearly 60. Adding Suarez alongside Naylor would dramatically reshape Seattle’s offense and make them a formidable contender in the American League.

Seattle’s First Step Toward a New Look Team

This trade could be the first of several moves the Mariners make before the July 31 deadline. The front office has demonstrated a willingness to part with promising pitching prospects to acquire proven major league talent. This approach reflects an all-in mentality for 2025, aiming to capitalize on the current window where stars like Cal Raleigh and Julio Rodríguez are in their primes.

What’s Next for Both Teams?

Seattle Mariners

The Mariners have reinforced their lineup and addressed a key positional need but still have work to do. The acquisition of Josh Naylor is a significant step, but Seattle’s pursuit of Auhaneo Suarez indicates they are not finished improving. Additionally, fans are hopeful that Seattle will add bullpen depth, possibly targeting relievers like Roldis Chapman from the Red Sox to strengthen their late-inning options.

Seattle’s ability to balance immediate major league talent with the long-term development of prospects will be crucial as they navigate the final stretch of the season and the playoffs.

Arizona Diamondbacks

For Arizona, trading away Naylor and potentially Suarez signals a shift toward selling mode as the trade deadline approaches. Acquiring two young pitching prospects in Garcia and Izzy gives the Diamondbacks some developmental pieces for the future. Garcia’s recent MLB debut and potential as a starter make him an intriguing asset, while Izzy offers upside if he can refine his control.

The Diamondbacks appear to be looking ahead, leveraging veteran players to restock their farm system and build for the coming seasons.

Final Thoughts

The Seattle Mariners’ acquisition of first baseman Josh Naylor from the Arizona Diamondbacks is a clear statement of intent. Naylor’s combination of contact skills, power, and plate discipline fills a vital hole in Seattle’s lineup and provides the team with a dependable everyday player at first base. Given the relatively low cost of prospects in Brandon Garcia and Ashton Izzy, this trade represents a smart move by the Mariners to improve their chances in the playoff race.

With the Mariners reportedly still targeting third baseman Auhaneo Suarez, Seattle could be on the verge of transforming its offense into one of the most feared in the league. Fans should be excited about the team’s aggressive approach this trade deadline and the potential for a deep postseason run.

As always, the trade deadline is a time of high drama and bold moves, and the Mariners’ first big splash could be just the beginning of what promises to be an exciting finish to the season.

What do you think about the Mariners acquiring Josh Naylor? Are you excited about the impact he will have on the team? Let us know your thoughts and predictions for the rest of the trade deadline and the season ahead.