Van der Sar turned 40-years-old at the end of October and it has long been expected that this would be his last season between the posts for United.
“I have come to accept this will be Edwin’s last season,” Ferguson told The People. “It’s sad but the difficulty for a goalkeeper when he gets to 40 is something which happened with Peter Shilton.
“All of a sudden, because of age, Shilton’s form just collapsed and I don’t think Edwin would want that. He is such a proud man and it’s going to be a big loss.
“We had a chat last season about how he saw his future and he explained to me his plans, and nothing has changed from then.
“It’s difficult because he has his wife’s health to consider after her illness.
“She is fine now and seems to be really good but she still has treatments to get in Holland, with physiotherapy and things like that. So for him to be here with us would be difficult.”
United have completed the signing of Denmark international Anders Lindegaard but Ferguson has hinted that he is considering bringing in another keeper as well.
He added: “We haven’t finalised our thoughts on the goalkeeping situation.
“Edwin has massive experience and you can’t buy that, so it’s a difficult one because he has been a great goalkeeper and will be hard to replace.”
