Manchester United will not appeal against a four-game domestic ban given to Casemiro after his red card against Southampton, with Raphael Varane backing them to cope in his absence.

A VAR review saw Casemiro shown a straight red card for a forceful challenge on Carlos Alcaraz during the first half of Sunday's goalless draw at Old Trafford.

The midfielder was also sent off in a 2-1 victory over Crystal Palace last month, making him the first United player to receive two red cards in a single Premier League season since Nemanja Vidic in 2013-14.

His second dismissal of the campaign means he must serve a four-match domestic suspension, missing Sunday's FA Cup quarter-final against Fulham as well as league meetings with Newcastle United, Brentford and Everton.

Erik ten Hag questioned Casemiro's dismissal after Sunday's game, claiming the 31-year-old is "tough but fair" and labelling the decision "debatable".  

On Monday, however, United confirmed they would not launch an appeal against the Brazilian's suspension, having determined "there was not a high chance of being able to overturn the ban".

United have suffered as many defeats in seven Premier League games without Casemiro (W3 D1) as in 19 (W12 D4) with the former Real Madrid man this term, while their win rate drops from 63.2 per cent to 42.9 per cent in his absence.

Varane, however, believes the depth of their squad will now come to the fore, saying: "He's a player who is very important for us. He brings balance to the team and to the squad. 

"But we have a great squad and we have to find another balance without him. We have good players in every position on the pitch and we are ready for the next games.

"I think he was very disappointed because nobody wants to be off the pitch before the end. We can't be happy with the decision he [the referee] takes but that's part of football." 

Casemiro will be available when United travel to Real Betis for the second leg of their Europa League last-16 tie on Thursday, after the Red Devils posted a 4-1 win in the first fixture at Old Trafford last week.