"I think at this moment now, Manchester is probably the biggest city in the world in terms of football," Carragher told Soccer AM.
"That'll come back to haunt me!
"In terms of football and managers, the players that have come in. You think of the world transfer record for Pogba.
"I think, now, certainly you can talk about the personalities on the pitch, off the pitch as well.
"They've got the two best managers in world football, and I expect these two teams to be going head-to-head for the next three or four years."