Unless he was wearing pinstripes, Aaron Hicks was actually one of the most underrated outfielders in MLB. He was absolutely despised in the Bronx, primarily because of two and a half consecutive seasons of below-average offensive production and a much too high $10.8 million salary. Every Hicks strikeout or routine pop-up was ridiculed endlessly and Yankees fans celebrated in the streets when he was finally designated for assignment and released on May 26.
He then signed a one-year contract with the Baltimore Orioles to replace an injured Cedric Mullins and was expected to continue his mediocrity on the O's bench, but as if suddenly imbued by the powers of a fresh start, he ended up posting an .858 OPS in June, including hitting four home runs and collecting 11 RBI.
Over the course of 236 plate appearances in Baltimore, Hicks slashed .275/.381/.425 for an .806 OPS (127 OPS+), the best he'd hit since 2018 (.833 OPS, 127 OPS+). He improved drastically in every area form his brief time with New York in 2023 and rediscovered his talents with a bat, helping propel the Orioles to their first 100-win season since 1980.
Signing Aaron Hicks has a few main benefits. First and foremost, he's great against lefties, putting together an outstanding .970 OPS against LHP. The Mariners were ever-so-slightly below average when it came to facing lefty-pitching, posting a .730 OPS in 2023. Second, he's got excellent plate discipline. He had a walk-rate of 13.5% last season and has averaged a walk-rate of 12.7% over his 11 year MLB career, all while consistently striking out at a league-average rate (21.5%). Third, given his relatively old age (34 years old), and marred reputation from his last few years in New York, Seattle might be able to pick him up for cheap. Spotrac estimates that he's worth roughly $900K, a bargain bin price for an above-average hitter.
On the other hand, Seattle already has a relatively talented player roaming center field by the name of Julio Rodriguez (not sure if you've heard of him before), but Hicks is also able to take a corner outfield spot if necessary, especially as one of the hardest throwing outfielders in the league (93.0 mph arm strength, 95th percentile). Dominic Canzone's spot in right field would be the most likely to be ceded to Hicks but Jarred Kelenic may relinquish his own spot in the lineup in a platoon situation given his lukewarm performance against LHP this season (.774 OPS). Hicks is also quite the capable fielder, so he might also find time in a more defensive-focused situation.
Aaron Hicks is a veteran and like so many names before him (e.g., Nathan Eovaldi, Jordan Montgomery, Aroldis Chapman, etc.) he seems to have gotten much better at baseball since leaving the Big Apple. We haven't seen the last of him just yet and despite so many attempts to write him off, he's still a free agent worth looking at for any team, especially the Seattle Mariners.