Donovan Solano - 1 year $5-$7 million
The first, and perhaps my personal favorite, under the radar free agent for the Mariners is Donovan Solano. Solano spent 2023 with the Minnesota Twins. He slashed .282/.369/.391 in 134 games played. He provided an 8.9% BB%, a 22.2% K% and an impressive 116 wRC+. Solano is not a power guy, but a career .280 hitter with impressive on base skills, and an average 112 wRC+ since 2019, he would add a lot of depth to this Mariners team.
Dylan Moore, Sam Haggerty and Jose Caballero accounted for 553 plate appearances in 2023, combining to hit .223. That is a huge chunk of at-bats that are waisted with below average hitters. There is no reason that Solano can't take away a vast majority of those at-bats and provide the offense with a little more depth. I think that the biggest reason Solano is a personal favorite of mine is that he would push at least 2 of those 3 guys to be AAA guys that are only needed if an injury happened. No way should those 3 account for basically an everyday player, number of at-bats.
In 2023, Solano played a majority of the time at first base, giving you a decent bat to backup or spell Ty France. But he also has spent time at 2B as well as 3B. Something that must happen next year is getting Geno down to about 150 games played and only about 130-140 in the field. Solano can fill in at third, or second and move Rojas to third. He is not an elite defender or probably even average, but he won't hurt you playing 20 or 30 games between 2nd and 3rd.
Solano won't get more than a 1-year deal, but I think something in the $5-$7-million-dollar range would get him to Seattle. That is slightly more than that of Dylan Moore, and while he isn't as good as Moore defensively, he would provide a lot more value offensively than Jose Caballero or Sam Haggerty and more consistency than Dylan Moore.