When Danish goalkeeper Peter Schmeichel quit Old Trafford in 1999 the club struggled for six years to sign someone of a similar calibre, eventually settling on Van der Sar having passed up the chance to snap him up from Ajax several years earlier.
"We'll be better organised about that this time," Ferguson told a news conference on Friday, the day after the 40-year-old Dutch keeper said he would retire in May.
Schmeichel's departure to Sporting Lisbon marked the start of an uncomfortable goalkeeping period with 10 different names standing between the posts in six years.
Massimo Taibi became a laughing stock and a regular in fan polls of a "Worst United XI", earning the nickname "The Blind Venetian" after a series of blunders, while Mark Bosnich was talented but besieged by off-field problems.
Raimond van der Gouw was mediocre, while the eccentric Fabien Barthez had a brilliant first season before his reckless antics in the penalty box began to cost United soft goals.
Just as when "Great Dane" Schmeichel left, Van der Sar will leave some very big gloves to fill.
"If you look at the career that Edwin's had, I think it's four Champions League finals, three World Cups, a fantastic career he's had," said Ferguson.
"Peter of course, as everyone recognised at the time was the best goalkeeper in the world, so I've been very fortunate having two magnificent goalkeepers."
LINDEGAARD READY
While United still managed to win three league titles in the period between Schmeichel's departure and his Dutch successor's arrival, Ferguson does not want to take chances again.
He has brought in 26-year-old Dane Anders Lindegaard, who could be in line for a debut in Saturday's FA Cup Fourth-Round match at League One Southampton as Van der Sar is not travelling with the squad.
Although Ferguson said he was not in the market for another goalkeeper, newspaper reports have speculated on who could eventually head to Old Trafford as Tomasz Kuszscak and Lindegaard are far from Van der Sar's league at present.
Established names such as Germany's Manuel Neuer and Rene Adler have been mentioned as well as Ajax's Maarten Stekelenburg.
Van der Sar set an English record in 2009 of minutes without conceding a goal when he went more than 21 hours unbeaten and has kept a cool head at key moments such as when he saved Nicolas Anelka's final penalty in the shootout against Chelsea in the 2007/08 Champions League final.
"He's had a fantastic career, a special man, really special," said Ferguson. "But he made the point himself: it is pointless trying to be superman into your 40s. It is one of the sad parts of my job that you get to the stage where age takes over."
