The friction between Pogba and Mourinho has been suggested countless times in the past, despite claims that there are no problems between the two.
The squad, which includes World Cup victor Paul Pogba and David de Gea, is said to have become a source of frustration for Mourinho following a lack of transfer activity.
"Jurgen Klopp gets the best out of his players, Pep Guardiola gets the best from his players, but there is a lot of wasted talent here".
Such inflammatory comments were never likely to go unpunished, with Mourinho reportedly gathering his players at United's Carrington training ground on Tuesday to reprimand Pogba and underline his authority.
"I am the manager, I can make these decisions, no fall-out at all, no problems at all, just one decision that I don't have to explain".
TV revenue rose 5.2% to £204m after the club finished second in Premier League last season, against sixth before. I would lie if I said we threw the match away. I wanted to bring a team who could really compete.
Asked about what is stopping the team from playing the way fans are often crying out for at Old Trafford, he said: "I can't tell you because I'm a player".
"I am trying to build a group to be successful and nights like this are incredible".
United are up against Derby County next in the EFL Cup tomorrow.
It levelled for Derby before Romero was sent off eight minutes later. "To go against world-class players and play that way, it's right up there", he added.