Manchester United manager Erik ten Hag has clarified Casemiro's spot in the team following the arrival of Manuel Ugarte.
Casemiro was hooked off at halftime in the 3-0 defeat to Liverpool before the international break.
The Brazilian was at fault for the two opening goals and received a lot of the criticism following the defeat.
Read: Ex-EPL star tears into 'diva' Bruno Fernandes
United signed Ugarte on the final day of the transfer window, but Ten Hag says Casemiro will still play a key role.
"You definitely need him, for sure," said Ten Hag, who revealed he has spoken to Casemiro about his role and the decision to sign Ugarte from Paris St Germain. "Of course I speak with him about the situation. Everyone can have a bad at the office - have you never had a bad day at the office?
"He [Casemiro] is experienced. I guess it's not the first time he's had to deal with a bad game, so he has to overcome this as well. But it's normal in life you have highs and lows.
"In your life and in the life of a football player, there are many people observing this and who have an opinion on this and you have to deal with this. He knows how to deal with it.
"Nobody's career goes only up, no team's pattern only goes up. Then you have to deal with it – then it is about what is the end result. I normally do talk to him and in this case I did as well, but players in our club know when you are playing at this level, there is always competition.
"They also know you can only be successful if you have a squad that has cover. You can't have a squad where you only have one player who can cover this – you need at least two for each position, sometimes three. Then it's about what is the best fit for the team. They have to prove it, that is the key word. They have to take responsibility and win games for the club."