Manchester United s Casemiro, (18) celebrates with teammates after scoring his sides second goal of the game during the English FA Cup 4th round soccer match between Manchester United and Reading at Old Trafford in Manchester, England, Saturday, Jan. 28, 2023. AP
The Brazil international was sent off in the second half for grabbing Palace midfielder Will Hughes by the neck and will now serve a three-match ban for violent conduct.
United is already without Christian Eriksen for the majority of the rest of the season because of an ankle injury and must now cope with the loss of another influential midfielder.
Casemiro was sent off in the 70th minute, shortly after Marcus Rashford had put Erik ten Hag’s team 2-0 up.
Following a tussle between both sets of players on the sideline, VAR asked referee Andre Marriner to review the footage of Casemiro and the decision was a straight red.
His absence was immediately felt as Palace set up a tense finish, with Jeffrey Schlupp scoring six minutes after Casemiro's dismissal.
Bruno Fernandes had opened the scoring early on from the penalty spot and United looked set to cruise to victory when Rashford added a second.
But in front an increasingly nervous Old Trafford crowd, Palace dominated once the home team was reduced to 10 men.
United held on for the win to move within eight points of leader Arsenal, which lost 1-0 at Everton in the earlier kick off.
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