The defensive specialist that crushes left-handed pitching - Michael A. Taylor
The Mariners are a team known for their pitching and defense. They have one of the best pitching staffs in baseball and have trotted out one of the better defenses each of the last couple of years, with guys like Julio, Kelenic, JP Crawford, Geno, and Cal all giving you above average to elite defense. Coming into 2024, there are certainly more question marks in regard to their defense.
The corner outfield spots will be occupied by a combination of Luke Raley, Mitch Haniger, and Dominic Canzone, which shouldn't inspire much confidence. Enter Michael A. Taylor, one of the best defensive outfielders in baseball. He posted elite metrics in outs above average (OAA) and defensive runs saved (DRS), while posting 90th percentile arm strength. Taylor could give Julio a day off (or a DH day) regularly while showing no significant defensive drop-off. He could also be a fourth or insurance corner outfielder who would give you elite corner outfield defense.
Check out some highlights from Michael A. Taylor's 2023, courtesy of The Baseball Hub
Taylor would also provide a lot of insurance and protection for both Luke Raley and Dominic Canzone. Both of those outfielders are left-handed, and Canzone figures to play into a platoon with Haniger, leaving Raley with a good chance to get a lot of at-bats. The part that is scary, is that if Raley struggles against lefties and Haniger gets hurt, you are rolling out two left-handed hitters quite often. Not to mention, your high minor's outfield depth (Marlowe, Trammell, and Deloach) are all left-handed as well.
Taylor slashed .252/.313/.602 with nine home runs in 112 plate appearances against lefties in 2023, which was good for a 146 wRC+. You could probably sign Taylor to a one-year deal, though it might take two years. It would probably take about $6-$9 million a year to get him, which is well within the Mariners budget (especially assuming his signing would likely result in Dylan Moore being traded) and would give them plenty of insurance.