Liverpool boss Rafael Benitez believes Chelsea's style of play means they cannot be described as a great side.
"Chelsea are a very good team, they are very difficult to beat," Benitez said ahead of Liverpool's Premiership encounter with the Blues on Sunday.
"But to me, Arsenal played much better football two or three years ago. They won matches and were exciting to watch.
"Barcelona and Milan too. They create excitement so how can you say Chelsea are the best in the world?"
Chelsea's tactics also came under fire from Dutch legend Johan Cruyff following the 0-0 draw against Liverpool in the Champions League on Wednesday.
The Blues head into Sunday's game with a 14-point lead over Liverpool in the Premiership, although the Reds have two games in hand.
Mourinho has heaped the pressure on Liverpool by claiming a draw would be a "very bad" result but Reds skipper Steven Gerrard says his side are confident of victory.
"If decisions had gone our way on Wednesday we'd have won so there's no reason to believe we can't win on Sunday," he said.
"We know we can get at Chelsea and that we can beat them."