Sometime within the next couple weeks, Eloy Jimenez and Tim Anderson will return from the IL. Barring additional injuries (which always seems more likely than not), two players will need to go. I've listed all six possibilities here. (I'm not including any discussion about Grandal because in the very unlikely event they moved/released him, it would be for another catcher and not Eloy or TA).
Gavin Sheets - Case for him to go: Can be optioned, has a .601 OPS overall and only .648 vs RHP, doesn't play any position well other than 1B. Providing no value of any kind to the team at all. Case for him to stay: there really isn't one at this point
The more difficult decision is the second one to go.
Jake Burger - Case for him to go: Can be optioned, assuming that Moncada is not headed for another IL stint, Burger is blocked at his position, he's also been dreadful vs RHP with a .580 OPS which is also the team's biggest weakness. Case for him to stay: He's been the biggest spark for this team the past week and is crushing lefties to the tune of a 1.174 OPS. There's clearly a scenario where he sticks around, getting 1-2 starts a week at 3B and also getting DH time vs LHP.
Danny Mendick - Case for him to go: When Anderson comes back, becomes one of four middle infielders on the roster, and he's the only one who can be optioned. Despite his hot start this season, has a .662 career OPS and isn't likely to keep it up. Case for him to stay: Right now he's outproducing Harrison and Garcia by a lot, could be sending the wrong message to the team to keep those two and send Mendick down.
Josh Harrison - Case for him to go: Putrid .541 OPS to date, costs less to release than Leury. Case for him to stay - costs more to release than optioning Mendick, has been hot this past week and might be turning things around
Leury Garcia - Case for him to go: absolutely obscene .464 OPS negates any value he has as a switch hitter, Vaughn's ability to play OF and Mendick's ability to play all IF positions negates his value as a utility player. Case for him to stay - would cost a lot to release, longest tenured Sox player, manager favorite.
Who I think should go: Sheets, then Garcia
Who I think will go: Sheets, then Mendick