This seems like a topic that's going to get more and more attention, so here's a thread for it. Let's start with a quiz (no cheating!)
Player A's recent season wRC+ (oldest first): 93, 132, 105, 104
Player B's recent season wRC+ (oldest first): 92, 128, 103, 104
One of these is Hosmer and one of these is Mancini, do you know which? More importantly, with as similar as they are does it matter?
Now, this comparison is misleading for a couple reasons. One is age, Hosmer is 2 years older. The other is 2020, that partial year represents Hosmer's one very good offensive season and Mancini didn't play at all that year since he was battling colon cancer. The interest and investment each received(Hosmer cut by Boston and then signed for league minimum, Mancini 2/14 w/ an opt-out) makes it clear that they aren't the same. But when I looked at it I was surprised how similar they were as hitters, especially when you consider Hosmer should be a clear upgrade defensively if you were to choose between them.
This is a drawn out way of saying that I think Mancini has a bigger part to play in Hosmer's fate than I might have realized. Mancini's background isn't so sparkling that we can assume that he's gonna put up an above average batting line in his sleep into his 30s, and while his output languishes(current wRC+: 26), it might prove harder to move on from Hosmer if he's at least providing separation between them even if the overall number isn't great. And Mancini's 2nd guaranteed year and background as a hitter means they believe enough in him to not pull the plug even after a horrific month, so paradoxically Mervis's MLB debut might be dependent not only on Hosmer not hitting, but on Mancini getting his act together offensively.