Seattle Mariners Assign Notable Prospect to Arizona Fall League

The Seattle Mariners will end their regular season in a game against the Los Angeles Angels on Sept. 27. Whether that marks the end of the 2026 season for the Mariners on the major league side of things or not, several of the teams prospects will be down in Arizona playing games in anticipation of a 2027 season that will have a lot of moving (or, more fittingly, stilled parts).

The Arizona Fall League begins Oct. 3 and will continue through Nov. 14. The Mariners will have several prospects, along with the Baltimore Orioles, Cincinnati Reds, San Diego Padres and Minnesota Twins, to compete with the Peoria Javelinas.

Seattle announced one of the prospects that will be competing with the Javelinas on Friday, and it's an interesting pick considering the context of the players who are usually competing in the AFL.

The Arizona Fall League's official account announced in a post on "X" that catcher Boston Smith, the Mariners No. 13 prospect per MLB Pipeline, will be participating in the league.

Smith is one of the new additions to Seattle's farm system. He was acquired by the M's, along with major league reliever Seranthony Dominguez, in a trade with the Chicago White Sox that sent veteran right-handed starting pitcher Luis Castillo to the Southside.

Smith was originally picked by the Washington Nationals in the sixth round of the 2025 MLB Draft out of Wright State and was traded to Chicago at the onset of this season March 28 in return for first baseman Curtis Mead.

This season was Smith's first in the minor leagues. He began the year with the White Sox's Single-A affiliate but quickly rose the ranks and was promoted to High-A on April 14 and then Double-A on July 1.

After the Mariners traded for him Aug. 2, he was assigned to the Double-A Arkansas Travelers and continued his stellar season.

With Arkansas, Smith slashed .220/.356/.514 with an .870 OPS in 30 games and hit three doubles, a triple and nine home runs with 22 RBIs.

Smith finished his first professional season having played in 109 games, and hit 31 homers with 80 RBIs.

Prospects are usually assigned to the Arizona Fall League to make up for at-bats or time missed during the regular season, or are prospects still in the infancy of their professional careers looking to build game play. Current and former Seattle 100 prospects, Jonny Farmelo and Colt Emerson, were two players who received at-bats in the AFL after missing time the previous season due to injury.

The current Collective Bargaining Agreement (CBA) between the MLB and MLB Players Association is set to expire Dec. 1. Teams will not be allowed to make roster moves after the expiration of the current CBA and have until then to add players to the 40-man roster.

Players in the minor leagues not on the 40-man roster will still be able to play the minor league season, as the MiLB has a separate CBA from the MLB.

Due to Smith only being in the organization for 30 games, it's possible the M's want to see more at-bats from Smith heading into next season. However, with the AFL season set to end before the CBA expires, it's also possible that the Mariners want to give Smith at-bats before he's not able to play if the team plans to add him to the 40-man roster.