As Sir Alex Ferguson begins his rebuilding job at Old Trafford this summer, he will hope the search for a successor to Edwin van der Sar doesn't prove as treacherous as his attempts to replace Peter Schmeichel.

Despite convincing Van der Sar to extend his United contract into his 40s, Ferguson knows he cannot expect the veteran goalkeeper to continue defy the years.

That is why he's spent the past 12 months monitoring Europe's finest goalkeepers in a bid to make the transition as smooth as possible.

In truth, he expected the situation of United's next No 1 to be resolved by now with Ben Foster given every chance to establish himself as Van der Sar's successor this season.

But a series of nervous displays at the start of the campaign saw the man who Ferguson once described as the future of both club and country demoted to third choice and eventually shown the door.

With Foster set to move to Birmingham this summer, Ferguson will now have to redouble his efforts to find a new goalkeeper with Tomasz Kuszczak unlikely to be given the chance to prove he can be No 1.

Lyon keeper Hugo Lloris is at the top of his wanted list at a cost of £15m - and Ferguson is considering making a bid before the World Cup in order to avoid the Frenchman's value sky-rocketing on the back of a successful tournament.

United targets

CSKA Moscow's Igor Akinfeev is another to emerge as a leading candidates after some outstanding performances in the Champions League, including a 3-3 draw at Old Trafford last November after which Ferguson spoke of his admiration for the Russian international.

Schalke's Manuel Neuer is an option with United goalkeeping coach Eric Steele making a personal check on the German international recently.

But Ferguson will be wary of entering an auction for the highly-rated 24-year-old, who is also a target for Bayern Munich.

Fiorentina's Sebastien Frey could prove the cheapest option at around £9m and crucially, at the age of 30, is deemed an ideal age to cope with the expectations at United.

As keen as he is on Lloris, Akinfeev and Neuer, with all of them under the age 25, he may be concerned that they won't have the temperament to make it at United.

Which is where Frey holds an advantage - as well as his relatively small fee in a summer when Ferguson will be looking to stretch his transfer budget as far as it can go.

Frey, a former French international, has been in Italy's top flight since 98, playing for major clubs Inter Milan, Parma and Fiorentina in that time.

One advantage Ferguson has in finding Van der Sar's successor, as opposed to Schmeichel's, is the fact that the incumbent keeper will be around to help smooth the transition.

But with the former Ajax and Juventus keeper turning 40 before the end of the year, he will know time is running out to fill his shoes.

Which keeper would you like to see United go for? Have your say.