Manchester United boss Erik ten Hag has reacted following his side's 1-0 defeat to Arsenal at Old Trafford on Sunday, with the Dutchman refusing to criticise Casemiro.
The Red Devils went into the game hoping to bounce back after Monday night's awful 4-0 defeat to Crystal Palace.
But United were sunk by a goal from Leandro Trossard in the 20th minute.
The Belgium international scored from close range after a good delivery from Kai Havertz, who had been played onside by Casemiro.
Man Utd boss Erik ten Hag was disappointed after his side lost 1-0 to Arsenal at Old Trafford on Sunday
PA
But Ten Hag has refused to criticise the veteran, with the Dutchman insisting his side made errors before Trossard's goal.
"It's small detail, one player makes a mistake and it opens up," the 54-year-old told BBC Sport.
"Before that in possession we could have done better in better positions and better options. It's details."
United's defeat to Arsenal comes just days after they lost 4-0 to Crystal Palace at Selhurst Park.
And while Ten Hag admits there are positives to take, he was still frustrated by his side's failure to get anything from the match.
"It's still disappointing. I want to win, it doesn't matter who we face on the pitch," he admitted.
"We have to win every game and give everything."
Pundits in the Sky Sports studio were critical of United, who have now lost 14 Premier League matches this season.
Wayne Rooney, who won every major trophy during his own time at Old Trafford, said his old side were now a team of individuals.
"With Manchester United they are so open at times it is incredible," he said.
"The space and the chances they are giving away is incredible.
"Any player in that defence I feel sorry for because it is such a difficult position to play in within that side.
"The team looks disjointed. It is a team of individuals, and that is a concern.
"You look even at the middle and bottom end of the table and there is a togetherness and compactness to them."
And Roy Keane said the Red Devils were 'so bad' as they crashed to another defeat.
LATEST SPORTS NEWS:
Casemiro made a huge mistake as Man Utd lost to Arsenal in Sunday's Premier League clash
SKY
"I think Arsenal will be thinking how lucky they were to play such a poor Manchester United team today," he fumed.
"The end product, the lack of quality, the decision making, people making mistakes and not putting demands on each other.
"No one digging each other out for mistakes.
"That United team out there today, particularly in the last half an hour, were so bad."
While it was yet another bad day for United, it was a huge win for Arsenal.
Man Utd were so flat as they lost 1-0 to Arsenal at Old Trafford on Sunday
PA
And Mikel Arteta hailed his side, though did admit they were guilty of some 'bad things' despite the result.
"We needed a result today in a really difficult place," he said.
"Our history was not in favour of a result today, there was so much at stake and we're happy with the result.
"We started the game really well and were dominant. We scored the goal and I think the goal led to slightly bad things because we started to play too safe, too sideways, too backwards with not enough structure.
"We started to give the ball away in good areas and that is a danger against them. But we defended well and didn't concede too much."
