And Ferguson says he rates the Dutchman among the club's greatest.
He said: "If Edwin comes through the Bolton game, he will have two very important away games against CSKA Moscow and then Liverpool. He couldn't come back at a better time. The calming influence he has on everyone around him is significant.
"Edwin's a fantastic goalkeeper - I think he and Peter Schmeichel have been the best two goalkeepers in the history of this club as far as I'm concerned."