Tuanzebe was making his first appearance for the Red Devils since December 2019 against one of the most formidable attacks in Europe, but United ran out 2-1 winners in the French capital thanks to goals from Bruno Fernandes and Marcus Rashford.
De Gea, who was called into action himself on several occasions against PSG, believes that Tuanzebe has now displayed his true capabilities after deputising for Harry Maguire at the Parc des Princes.
Speaking to MUTV, De Gea said: "He has been unbelievable today. He played against two of the best players in the world in Neymar and Mbappe so he did really, really well. I am really happy for him.
"He has been in difficult moments with the injuries but now he has shown today that he is capable of playing in big games."
United's next fixture sees Ole Gunnar Solskjaer's men welcome Chelsea to Old Trafford for Saturday's Premier League showdown. body check tags ::