I don't really get this deal so far. I think he's awesome as a player to have but we already have Pogba/Fagioli - Locatelli - Rabiot on our roster. I'm guessing he can't play as a lone DM so he'd take Pogba's spot who has injury problems. But that position doesn't seem like our most problematic imo.
To me it seems like we need a LB, #10 and maybe a DM more rather than a B2B midfielder imo.
Only way for this to make sense is to ga with a 4-3-1-2 but then we really need a #10 as well