David de Gea reacts to Middlesbrough's controversial equaliser vs Manchester United in FA Cup

Manchester United goalkeeper David de Gea has expressed his disbelief at Middlesbrough's equalising goal at Old Trafford in the fourth-round of the FA Cup on Friday night being allowed to stand.

Trailing 1-0 to Jadon Sancho's first-half effort, Middlesbrough got themselves back on level terms in controversial circumstances with 64 minutes on the clock.

Duncan Watmore, who had stepped off the substitutes bench just a few minutes earlier, brought a brilliant ball from Isaiah Jones down under his spell on his right foot before it bounced up onto his right hand and he played a right-footed chipped pass into the path of Matt Crooks to slide the ball home.

Crooks raced away towards the travelling contingent of Middlesbrough fans to celebrate, with almost everyone inside Old Trafford expecting the goal to be chalked off by referee Anthony Taylor.

However, the goal was allowed to stand despite close analysis by VAR, with it deemed as "accidental handball."

Whilst United's players surrounded referee Taylor in disbelief, De Gea, who is not involved this evening, reacted on social media, quote tweeting Rio Ferdinand's tweet about the goal with a shocked emoji face.

Ferdinand had tweeted: "What's the point of VAR...."

Despite United's disbelief about the goal being given, whistle-blower Taylor, as well as the VAR team - was correct to give the goal, with the handball rules stating that accidental handball committed by a player that didn't score the goal in question is allowed to stand, with that coming as a result of the rule changes.

Former Leicester City and England striker Gary Lineker reacted to the goal being awarded, insisting it was the correct decision, but blasted the handball rule as a whole.

He tweeted: "The right