I kind of understand Inzaghi in terms of keeping Mkhi for 90 minutes, even though I'd prefer him to get more rest. Even if he looks tired, Mkhi has this ability to get bursts of energy in terms of his forward runs in the last minutes of matches. Just thinking of his assist yesterday and also penalty won vs. Torino in the last minutes.
Regarding Bastoni, I don't think it's about him not being able to play 90 minutes (he's played 90 minutes 13 times this season) but he is a lot more involved in our attacking play than someone like Acerbi. Even though Bastoni plays as a centreback, he doesn't have the typical role a centreback in a back 4 would have - centrebacks in a back 4 rarely ever get subbed off but they do not contribute as much to attacking play as someone like Bastoni does.
I do agree on Darmian though - the guy really needs a rest. Even yesterday, there were a few instances where he was just late to the ball and you can tell he's gassed. I would have considered putting on Bisseck and letting Pavard play the role for a bit, if Buchanan wasn't ready for whatever reason. I do think Buchanan should have played given how much we had the game under control and how well we were playing in attack - it would have been a good situation for him to get some minutes.