The big stick with middle of the order potential, but is not great defensively - Adam Duvall
The Mariners currently are a little scary defensively, but over the years, they have struggled to find some middle of the order offense. Where Michael Taylor gives the team a lot of value defensively, and has hit lefties well recently, Duvall crushes both righties and lefties. This makes a lot of sense for a lot of the same reasons as I stated talking about Michael A. Taylor, but Duvall just can't give you the backup centerfield defense that Taylor can. What Duvall gives you is one of the most underrated bats in the game.
Check out these highlights from Adam Duvall, courtesy of Harrisonwitz99
We talked a lot about Duvall, and he is one of the most underrated bats in baseball. Duvall has been especially good over the last four years, running a slugging percentage of .530, which puts him in the top 40 in all of baseball. During that same time span, he has hit a home run once in every 13.45 at-bats, which puts him on a 37-home run pace in 500 plate appearances. Duvall would give you what would probably be considered one of the best number four or five outfielders in all of baseball.
Duvall isn't great defensively, though he is a former gold glover, he just isn't on that same level anymore. He is a solid corner outfielder, however, with surprising athleticism for a guy of his stature. He probably won't be able to spare Julio a day in centerfield, but he can definitely hold his own in a corner spot. Duvall shouldn't be too expensive either. He is 35 years old, so a one-year deal should be all it takes. They could probably get him to come to the pacific northwest with a salary of around $5 million or so.