De Ligt has played every minute of Premier League action so far and celebrated his return to the Netherlands squad by heading home the dramatic equaliser in the 2-2 draw at Tottenham Hotspur on Saturday.
Mazraoui played with Matthijs at Ajax and Bayern Munich and the pair are close friends, who joined United on the same day.
Their relationship and trust enables them to critically analyse each other's games but Nous is in no doubt that his pal is starting to show the kind of consistency that earned him the Golden Boy award for the best young player in Europe, back in 2018.