And in the very first minute of the match, Maguire needed medical attention.

He headed Fulham striker Rodrigo Muniz’s shoulder as he defended against the Brazilian.

A few moments later, he had the ball under no pressure and deliberately played it out for a throw-in before immediately bending over.

He looked dazed and dizzy as he took a seat on the pitch, putting up a hand of apology.

A shaken Maguire, 30, appeared to have taken a knock around his left eye and team-mates rushed to check on him.

The former captain needed to be checked over by the United docs to ensure he was safe to continue as Raphael Varane warmed up on the sidelines.

TNT Sports commentator Darren Fletcher described the incident as “very concerning”.

But after a lengthy stoppage, Maguire was given the all clear and allowed to continue.

However, supporters voiced their concerns that Maguire could be concussed – and called for a fuller head injury assessment.

He tweeted: “Maguire clearly dazed!! Why on earth doesn’t football just adopt HIA protocol like rugby?

“He’s just taken a head injury and as a centre back is likely to have to repeatedly head the ball in the next 40mins. When will we learn?”

Another wrote: “Maguire seems okay, but I think football is in the dark ages letting him play on immediately.

“Allow for a proper ten-minute head injury assessment and bring on a ‘concussion’ sub.”

Maguire was back in the thick of the action within a couple of minutes as Scott McTominay thought he put United in front.

However, the goal was ruled out after a VAR check because the England international was offside and made an attempt to play the ball from the original free-kick, which Alejandro Garnacho got on the end of to square for an easy tap-in.

In the second half, Maguire keeled over again and was once more assessed by the doctor but still carried on.

Referee John Brooks waved on the medic who talked to the £85million defender – before he was allowed to return to the field and continue, playing the full 90 minutes.

The defender looked dazed as he received treatmentFans called for a full head injury assessment to be undertakenMaguire was offside as Scott McTominay’s opener was ruled out