It has already been established Manchester United will be trying to sign at least two central midfield players in the summer.

Casemiro’s impending departure creates one space but the reality is there is no depth.

Kobbie Mainoo’s absence with what Carrick said before the game was a “small issue” deprived Manchester United of an effective link between defence and attack, someone who can take the ball in tight spaces and move it on quickly.

It sounds simple, yet when it is not there, the loss is all too apparent.

Manuel Ugarte does not have Mainoo’s control on the ball, or his awareness. The Uruguay midfielder was not Manchester United’s worst player, but he lacks the ability to lift a toiling team.

He works hard and hopes someone else can create the magic. This is not enough for where United are, let alone where they want to be.

It will probably be Thursday, when Carrick is due to speak to the media again before the Chelsea trip, when an indication of Mainoo’s availability for Chelsea and beyond will be clarified.

If the England international is missing again, it will be a major issue, even if Carrick tried to make light of it.

“He has been fine when he has played since I have been here,” he said.

“This was a tough game, a tough night – not just for him. When we went down to 10 men I thought he was really important and did a lot of covering for other players.”

Carrick also took the bold decision to leave Bryan Mbeumo on the bench for the first time in the Premier League this season. It did not work.

Neither Mbeumo nor Amad Diallo have found their form since returning from Africa Cup of Nations duty. Matheus Cunha flits in and out of games and Benjamin Sesko – who had the home side’s best two chances and was unlucky not to find the net – has been more effective off the bench.

It means the burden falls on skipper Bruno Fernandes to create opportunities.

Fernandes claimed a 17th Premier League assist, three short of the record for a season, when he crossed for Casemiro to head home. But deep in stoppage time, when he had the chance to cross deep into the penalty area again, he only found a Leeds head. Someone has to share the responsibility.