Mariners keep an eye on coaching development in the Arizona Fall League, with Cowan and Gargas leading the way

The Arizona Fall League is operating in Phoenix this week with its usual blend of prospects from across Major League Baseball, but at least one part of the assignment is about more than player evaluation. A Yahoo Sports scouting look notes that some clubs also treat the league as a temporary training ground for coaches, sending staff members who can gain experience across organizations and work with a wide range of prospects and playing styles.

For the Seattle Mariners, the article highlights two Mariners coaches as part of that approach. Jordan Cowan, described as a long-tenured Mariner, is working as the acting hitting coach for the Javelinas during the AFL slate. The pitching side is handled by Dylan Gargas, who the story identifies as the Javelinas’ pitching coach for the fall league.

The core idea, as framed in the report, is that the AFL environment can expose coaches to different organizational philosophies while still preparing them for big-league expectations. Coaches do not just get time with their own system’s players, the report suggests, they also spend days with prospects drawn from many teams, which can change how a staff communicates, adapts plans, and responds to individual hitters and pitchers.

That matters for Seattle because the Mariners, like every organization, have to think beyond a single season. Even when the major-league coaching staff is stable, teams constantly evaluate who can handle specialized roles, how staff members collaborate, and which coaches can translate instruction quickly when the roster is not built from familiar names.

Cowan’s placement as acting hitting coach stands out in the report because it is tied to tenure inside Seattle’s program. The implication is that the Mariners are willing to put their institutional knowledge into a rotating, multi-organization setting, where hitters from around MLB come with different swing paths, approach habits, and developmental histories.

On the pitching side, Gargas is the identified Javelinas pitching coach in the piece. The AFL is known for compressing a pitching population that would normally never meet in one place, which can force pitchers and coaches to adjust to new arm angles, different breaking-ball usage, and varied scouting looks within a short window.

What to watch next is whether the Mariners’ staff use the week to gather actionable takeaways that can follow them back to the regular-season clubhouse and the broader developmental pipeline. The Yahoo Sports write-up points to additional coverage of Cowan and Gargas later in the week, which would be the clearest place to look for more specific details about what the coaching work has emphasized and what responsibilities each coach is taking on during the fall league.