Mourinho celebrated the first major silverware of his United reign when his team beat Southampton 3-2 at Wembley last season.
But after watching United kick off their defence of the trophy with a 4-1 win over second tier strugglers Burton at a well below capacity Old Trafford on Wednesday, Mourinho conceded the tournament often does more harm than good.
Mourinho showed where the League Cup ranks on his priority list by making nine changes as Marcus Rashford, Jesse Lingard and Anthony Martial scored United’s goals.
Even Burton boss Nigel Clough, more concerned with Championship survival, made nine changes to reduce the tie to virtual reserve clash status.
The fact Burton view the early weeks of the league season as more important than a trip to Old Trafford highlights the issues with a competition that Mourinho believes could be dispensable.
“You know, if the competition is an official competition, it is important for Manchester United and for me as a manager and I want the players to think the same way,” Mourinho told the BBC.
“If you ask me could English football survive or even be better without this competition? Maybe.
“Maybe we would be fresher for European competitions, for example.
“But we have this competition, we have to respect, we have to respect the sponsors, we have to respect the opponents, we have to respect the professionalism of all of us trying to do the best.
“If we can win it, we win it. If we don’t win it is because the opponents were better than us.”
Mourinho has won the League Cup four times, including three with Chelsea, while United have lifted the trophy five times.
His criticism about a competition that has run since the 1960-61 season came on a night when Manchester City, Chelsea, and Arsenal all went through to the last 16 despite fielding under-strength teams.