The midfielder is full of praise for the Belgium fullback, who has battled to displace Daniel Alves from the right-back position this season.
But Rabiot says: “He is a player we did not really know and we were all pleasantly surprised. He is an atypical player who has a lot of potential and who is hardworking. He has qualities that we did not suspect. He really is a reinforcement of weight.”
Meanwhile, United are being linked with RB Leipzig defender Dayot Upamecano.
Calciomercato.com says United and AC Milan are interested in the French youngster, with both giants preparing January offers.