One of the Red Sox’s longest tenured players is on his way out.

Free agent outfielder Rob Refsnyder has agreed to a one-year deal with the Seattle Mariners, the club announced Monday afternoon.

According to Ken Rosenthal of The Athletic, Refsnyder’s deal is for $6.25 million and includes $250,000 in incentives.

Refsnyder departs after four seasons with the Red Sox, during which he became a key veteran leader and a valuable right-handed bat off the bench.

The 34-year-old is coming off a productive 2025 season in which he batted .269 with nine home runs, 30 RBI and a .838 OPS in 70 games. He should now provide a boost to a Mariners club that is coming off its first AL West championship since 2001.

During his time with the Red Sox, Refsnyder became renowned for his ability to crush left-handed pitching. Last season he batted .302 with a .959 OPS against lefties, and for his career he owns a .281 average and .826 OPS against southpaws.

But while Refsnyder was highly regarded within the Red Sox clubhouse, his position may have grown tenuous given the team’s outfield logjam.

The Red Sox are already trying to find playing time for outfielders Roman Anthony, Ceddanne Rafaela, Jarren Duran, Wilyer Abreu and Masataka Yoshida, which won’t leave as many opportunities for an additional outfield bat.

The decision to move on may have also been made easier by the emergence of Romy Gonzalez, who hit .331 with a .978 OPS against lefties in 2025 and could plausibly fill Refsnyder’s role as lefty killer off the bench. Red Sox manager Alex Cora has also spoken highly of reserve outfielder Nate Eaton and his potential to impact next year’s club as well.