Former Manchester United midfielder Paul Scholes admitted Casemiro was a "big loss" for the Reds as Erik ten Hag's side lost away at Newcastle.
The Brazilian midfielder was absent as he continues to serve a four-match ban after being sent off in the goalless draw with Southampton last month. He will be sidelined for the next two domestic matches, which is a blow for United given how disappointing they were against Newcastle on Sunday.
Eddie Howe's side secured a 2-0 victory over United at St. James' Park, with Joe Willock and Callum Wilson both on the scoresheet for the home side. The result saw the Magpies move above the Reds in the Premier League table.
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Casemiro has impressed at Old Trafford since arriving from Real Madrid last summer, registering five goals and six assists in 38 appearances for Ten Hag's side. His absence in the middle of the park was felt against Newcastle - and Scholes insisted they missed his 'experience and leadership'.
Speaking on Premier League Productions, he said: "Casemiro is a big loss - we’ve seen what he’s brought to this Manchester United team in terms of experience and leadership.
"Newcastle played really well, if you walked away from this game and they’d scored four or five you wouldn’t be surprised. Man United need a big bounce back after that."
Meanwhile, Owen Hargreaves suggested Newcastle 'shouldn't be competing' for the Champions League places, but praised Howe's side for their performance against United.
"Personnel-wise this Newcastle team shouldn’t be competing for a Champions League place," he said. "Eddie [Howe] has done a great job because they’re outperforming themselves. He will be so proud of this team and his players."
Former Reds striker Andy Cole also discussed the fact United could drop to fifth position if Tottenham overcome Everton on Monday night. Should Spurs manage to beat the Merseyside outfit, they will move above the Reds into fourth.
"I’ve been watching Newcastle over the last few weeks and this is what the performances have been like," said Cole. "Things change so quickly - we were talking before the game about Manchester United being in a great position, they could be fifth tomorrow.
"Newcastle have been waiting years for this. Can you imagine them spending money in the summer knowing they have Champions League football?"
The Reds will have the chance to bounce back from the disappointing defeat when they welcome Brentford to Old Trafford on Wednesday night.
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