Boston Red Sox
A few teams are guaranteed to always be in the conversation for top free agents, and the Boston Red Sox are near the top of that shortlist. The Yankees already gave Gray a spin and probably won't be circling back, although don't count anything out with them.
More realistically, if Gray does a second tour in the AL East it will be in Boston. It provides some nice revenge opportunities but it makes sense over the long term for the Red Sox. Gray only has a few more years left in his career, but he'll probably be pitching into 2026 at some sort of productive level.
Boston needs a replacement for Chris Sale, which Gray could help provide.
Sale is locked in for 2024 at $27.5M with a full no-trade clause, which is brutal for Boston. The first chance the team has to move from him is 2025 when they can decline his club option and save $25M by doing so. At that point, if all goes well, Tanner Houck and Kutter Crawford will be top starters and Gray can fill in the Sale role as the veteran leader.
Something that makes this even more possible is if Thad Levine gets the GM job in Boston. There's no guarantee he'll take Gray with him, but there's a natural incentive to take one of the best successes he had in Minnesota and bring it with him to his new job.