Mourinho is seen to confront Pogba about the video in the Sky Sports footage, in an attempt to establish whether he was making light of the shock penalty shoot-out defeat.
Former United striker Alan Brazil, who played 41 times for the club during the 1980s, took aim at Pogba on his talkSPORT show on Thursday morning.
Pogba and Mourinho then had a hostile stand-off in training on Wednesday, with cameras capturing the frosty exchange.
'Now another question is should Mourinho be getting more out of a £90m player?
Mourinho has previously been linked with an exit from United after the club's poor start to the new top-flight campaign, and Barcelona are said to be monitoring the situation ahead of a potential bid for Pogba.
President Donald Trump boasts of 'very, very large brain'
The U.N. has attempted to broker a peace deal with the Iran-backed Houthi insurgency. "The United States is respected again". But Macron's harshest criticism had to do with the Paris climate agreement, which Trump withdrew the US from in 2017.
Mourinho's latest clash with Pogba has left some players bemused by his actions, especially after he stripped the Frenchman of the club's vice-captaincy.
You don't need me to say it.
"I am the manager I can make these decisions".
It followed comments made by Pogba after last weekend's disappointing home draw against Wolves where he moaned about his side's defensive tactics. "We are here to attack", said Pogba. "When we play like [that] it's easier for us".
A source close to Pogba's agent, Mino Raiola, has further revealed that Mourinho has already lost his greatest asset in the dressing room - the very ability to "cajole, read, and relate to his players".
Hughes played under Sir Alex Ferguson at Manchester United during the 1980s and 1990s, and while Ferguson adopted a tough approach, Hughes suggested their conversations did not usually stretch beyond team selections.