Josh Naylor, Mariners agree to 5-year contract, sources say

First baseman Josh Naylor and the Seattle Mariners have agreed to a five-year contract, sources told ESPN on Sunday, reuniting one of the top free agent bats available with the team that made signing him its top priority this offseason.

Acquired at the trade deadline by the Mariners, Naylor, 28, made an immediate impact offensively, defensively and on the base paths, solidifying a position that had been a weakness for Seattle.

The five-year deal, which is pending a physical, is the first major signing of baseball’s offseason and adds Naylor to a strong Seattle core that helped the Mariners reach Game 7 of the American League Championship Series. He joins AL MVP runner-up Cal Raleigh, star center fielder Julio Rodriguez and a deep Mariners rotation as they look to reach the first World Series in franchise history.

With her high motor skills and infectious energy, Naylor immediately found a home in Seattle. In 54 games with the Mariners, Naylor hit .299/.341/.490 with nine home runs, 33 RBIs and 19 stolen bases in 19 attempts. An average fielder at first base, he helped the Mariners win their first division title since 2001, then hit .340 with three home runs in 12 playoff games.

Combined with 93 games with the Arizona Diamondbacks this season, the left-handed Naylor hit .295/.353/.462 with 20 home runs, 92 RBIs and a career-high 3.1 WAR. An aggressive hitter with excellent contact skills, Naylor ranked in the top 20 with the lowest strikeout rate among qualified hitters.

The most shocking part of Naylor’s season: He went 30 of 32 in stolen base attempts, despite being one of the slowest runners in the majors, ranking only in the third percentile in sprint speed. Naylor often got a lead at first base and was perfect in base stealing attempts with Seattle, although teams became more aware of his tactics.

The Diamondbacks acquired Naylor last offseason from the Cleveland Guardians, where Naylor hit 31 homers in 2024 and made the All-Star team. During his seven-year career, Naylor hit .269/.329/.447 with 104 home runs, 435 RBIs and 55 steals, appearing in four postseasons.

Originally drafted in the first round as the No. 12 pick by the Miami Marlins in 2015 out of Mississauga, Canada, Naylor is the oldest of three baseball-playing brothers: Bo Naylor, drafted No. 29 in 2018, is a catcher with the Guardians, and his younger brother, Myles, was the No. 39 pick in 2023 and is a third baseman in the Athletics system.

ESPN’s David Schoenfield contributed to this report.