There is a little time left for Lisandro Martinez to become a Manchester United player now. Manchester United made an offer worth more than 40 million euros the last time. Ajax seemed contented with this offer. The player himself also wants to join them and reunite with his old coach too. I don't see any issue in this deal from now on. By this transfer Manchester United would replace Harry Maguire with him and have a more reliable defense line. I don't think Martinez would have issues with adapting as he is going to play with Erik ten Hag's game plan.
I even saw Manchester United have to pay at least 55 million euros in bonuses etc to get this player's signature.
I think if you look at the moment that Ajax are quite satisfied with the offer and this will probably happen in the last few days regarding this player's move.
Of course this is a good thing because Lisandro Martinez has been one of the standout players for Ajax this season.