#5 - Mitch Haniger; owed $16 million this season, can opt in next season for $17.5 million
Haniger was added by the Mariners as part of a deal that sent Robbie Ray to San Francisco in the off-season. Mitigating the deal some is the $6 million San Francisco sent to Seattle to help off-set the 2024 salaries included. If Robbie Ray were still in Seattle, his contract would certainly be higher on this list.
Haniger has not shown much to inspire confidence in his second go-round with the Mariners. Of the 24 Seattle position players who have at least 5 plate appearances, Haniger's -0.5 fWAR ranks...24th. Haniger makes the most money this season of all their position players, and the 33-year-old is posting a paltry .208/.286/.340/.625 slash line. Given how poorly Haniger has hit, on a team that desperately needs hitting, it stands to reason that Haniger will opt into his $15.5 million player option. He would not receive anything close to that on the open market.