United have stumbled to those victories against Brentford, Sheffield United and Copenhagen, with a vastly improved performance required if they are to lay a glove on Pep Guardiola's men.

The midfield battle looks key and Ten Hag says his side may be missing Casemiro for a third straight game, with an ankle injury sustained on Brazil duty putting his place in jeopardy.

"Aaron [Wan-Bissaka is back] in training today [Friday] and Case is a race against the clock," Ten Hag said. "No, not 100 per cent."

Casemiro had trained ahead of Tuesday's Champions League clash against Copenhagen - a group match he was unable to play in due to suspension.

The Red Devils were made to sweat in a narrow 1-0 victory against the Danish champions, with Andre Onana producing a stoppage-time penalty save that saw the under-fire goalkeeper mobbed by team-mates.

And Sunday's game is one that could define United's mood at a key stage of the season.

"Definitely you see we are back where we wanted to be in that this is a hard team to beat," Ten Hag said. "They find a way to win, so we are going in the right direction.

"I think it's a match above many other derbies. It's so huge because it's Manchester, internal.

"But I think it's also about world football and all the eyes will be on this game global wide.

"They're six points ahead, we're six points back, so we have to catch up. We know we have to progress the team, so we have to make developments."