The Russian branded United's performance a "disaster".
Kanchelskis, who also played for City, told Sport-Express: "Conceding six goals in the derby is a nightmare and a disaster. The problems at Manchester United continue.
"A team that sets themselves big goals concede six to City, that's terrible! I don't know how they play defensively, what they do. In my time, I think Sir Alex didn't exactly praise us. It would be hard for us to leave the locker room.
"The bust-up would be great! A lot of things would fly off the table to the side! So far, unfortunately, City are the favourites. It used to be that we destroyed them 5:0 ..."