I don’t think it was a matter of valuing Casas over Devers. It was a matter of Devers prioritizing his feelings over the needs of the team.
When Casas went down, the Sox needed a 1b., and there wasn’t one on the horizon Save a couple AAAA options (one of whom, Toro, has been stellar so far) If Devers moved to first, it becomes easier to fill the DH role. Maybe they activate Yoshida. Maybe they call up Anthony sooner. But neither of those guys is an option for 1b…