Schmeichel has hailed Ferdinand and Vidic as Manchester United's best defensive partnership since Steve Bruce and Gary Pallister.
Bruce and Pallister are regarded as United's greatest pairing but Schmeichel, who played behind the duo, believes they could be eclipsed.
"I definitely see similarities," said Schmeichel. "I loved playing behind those two, and Rio and Vidic are on a par with them. Brucey had great heart and Pallister was superb on the ball.
"You can see similar traits in Rio and Vidic. For me, Vidic has been the key to the defence and he's made Rio into a top-class player."