City cut United's lead at the top to five points on Wednesday and will slash it to two if they win at Carrow Road. However, Mancini is wary about the trip to East Anglia which comes just three days after the victory over West Brom.
"United is easy," he said. "We could lose or we could win but it is an easy game. Against United or Chelsea, our concentration will be 100%. Norwich will be really tough because we have only had two days to recover after West Brom."
It seemed Mancini had his tongue firmly lodged in his cheek as he delivered the comments.
Indeed, his entire press conference was conducted in that confusing manner as he backed the comments of United assistant manager Rene Meulensteen that the Red Devils have greater togetherness.
"I agree with him," said Mancini.
"They have big experience and are a fantastic team. We are nothing.
"But sometimes the best team, or the team that has balance, doesn't win."