He'd be a great second new CB of the summer (for free of course), since we need two new in an ideal world anyway, but we still need to actually buy a world class CB, and get rid of Pique (retire/MLS), Lenglet (sell him for 20M), Umtiti (release) and possibly Mingueza, although I don't mind the last one staying as the 4th/5th CB option for depth. A true world class CB (De Ligt, if we can afford him) or at least a great young talent (someone like Gvardiol would be pretty nice) to partner up with Araujo, Garcia and Christensen as backups, and Mingueza as the 5th option, if he wants, otherwise sell him too, even though we wouldn't get more than 10M for him anyway, so he might as well stays.
I'd still like Azpi too, but for backup RB more (since we're selling Dest, hopefully releasing Roberto and I don't think Alves should play beyond the summer: in a perfect RB world get in Mazraoui for free, then Azpi also for free as the backup, while Alves can join Xavi's coaching team if he wants) or as the RCB if we play 3 at the back.