The Brazilian struggled badly against Arne Slot's Liverpool side which dominated the game and capitalised on multiple mistakes from the midfielder who has been used as a scapegoat by United fans.
Casemiro was strongly linked with a move to Saudi Arabia this summer but opted to stay at the club and now looks to remain at the Reds for another season which has sparked controversy.
Casemiro's wife, Anna Mariana Casemiro defended her husband on social media after the game with a simple message.
"Alway's strong @Casemiro. The biggest," followed by a fiery love heart emoji.
United boss Erik ten Hag also defended Casemiro after many said the veteran midfielder left Old Trafford once substituted.
“I met him after the game in the dressing room, so he didn’t leave the stadium at half-time,” Ten Hag said. “Why I subbed him was because we are 2-0 down against an opponent as Liverpool, with their qualities, they are very good.
“We had to take risks because we want to bounce back, then you need players in midfield to cover ground, therefore we put Toby Collyer on the pitch.
“I think that in football everyone has to take responsibility. I’m sure he is a great character and he won everything in his career that you can imagine. I am sure he will keep contributing to our team and Casemiro is always winning so he will be there.”