Jose Mourinho has singled out Scott McTominay as the only Manchester United player who silenced Barcelona during their Champions League game.
Lionel Messi and co ran away with a 1-0 victory at Old Trafford as United failed to register a single shot on goal.
The Spanish side were unable to score more than one goal in the match as the Red Devils kept the likes of Messi, Luis Suarez and Philippe Coutinho at bay.
"Barcelona was not Barcelona yesterday," Mourinho told Russia Today.
"I think United had one player that was responsible for that because I think Scott McTominay in midfield he was like what I used to call - but when I use this expression it's obviously in the total positive sense of the word. He was a mad dog.
"Afraid of nobody. Imposing his respect. Pressing really hard with a huge range of movement a huge area of pressing.
"Pressing higher and creating problems in Barcelona building up then really aggressive on the duels."
Mourinho was not the only one pleased with the Scotsman's performance against Barcelona, United boss Ole Gunnar Solskjaer also said: "He's developing every time he plays.
"He comes into training every day with a fantastic attitude. That is the way to improve. Every game he plays, he grows and grows.
"He was the first one to take the ball down and settle us. We had to slow the game down. We were too quick to give the ball away. The three midfielders did really well."