That’s not really how football works. You can’t just buy loads of players to cover a previous injury crisis. Teams sometimes go down to having to get an emergency loan for a goalkeeper, but once they are fit, they would be stupid to go and buy another 3 senior goalkeepers on the basis that they would have actually gotten to play if they were at the club the previous season.
IF a good offer for Lindelof/Maguire comes - the clubs should take it. And if and when that happens, they should also buy a replacement, be it De Ligt or anyone else. We were in the same position last summer, nothing has changed. We had accepted a bid for Maguire, and would have bought in probably Todibo if he left. But he didn’t, so we didn’t. Instead, Maguire stayed and played. Numbers wise, we are no different from then having signed Yoro.
We are waiting to sell a RB so we can bring in Mazraoui. Why not just bring in Mazraoui anyway? We need to do squad building with sense. If Maguire stays, he can play. And if we feel he isn’t even up to that, then we need to be actively seeking a buyer for him, leaving him out of the tour etc because the manager sees no role for him. But that isn’t the case, the manager will use him if he’s here, and as far as I can see - he is.