Marcus Rashford was sent off by his teammates after appearing to argue with a Man United fan during the warm-up.
Marcus Rashford appeared upset by a Manchester United fan's comments during pre-match warm-ups on Wednesday night.
In images shared on social media, a supporter in the lower tier of the Stretford End appeared to shout something at him.
Rashford He cut a confused figure while participating in warmups with his teammates before walking up to the fan and responding.
It's not clear what was said, but a waiter at the field waved his hand at the fan as if to tell him to calm down.
Another clip shows Christian Eriksen and Antony apparently telling Rashford to move away from the stand amid the confrontation.
He then walked towards the center of the pitch at Old Trafford before the start of a crucial match for Unitedwhich saw them take on Newcastle.
Both they and Newcastle are fighting for the last European places alongside Chelsea, who face Brighton.
United took the lead in the 31st minute thanks to Kobbie Mainoo, his fourth goal of the season.
Newcastle equalized early in the second half through Anthony Gordon, but Amad Diallo and Rasmus Hojlund scored to restore the hosts' lead, with Lewis Hall making it 3-2 in the end.
European qualification would be a welcome end to United's season, which has fluctuated since opening day.
They also have an FA Cup final to play on May 25 against rivals Manchester City as they chase more silverware under Erik ten Hag.
There are still doubts over the Dutchman's future at Old Trafford amid an overall disappointing campaign.
Former Chelsea manager Thomas Tuchel has been linked as a possible replacement at the end of the season.
However, talkSPORT understands that he appears prepared to stay at Bayern Munich even though they announced earlier in the campaign that he would be leaving this summer.