Dutchman Van der Sar has made more than 150 league appearances for the Red Devils since arriving from Fulham in 2005, but the keeper will turn 40 in October and is expected to retire at the end of the current campaign.
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Old Trafford boss Sir Alex Ferguson had both Ben Foster and Tomasz Kuszczak on his books last season and would have hoped that at least one of the pair could step up to fill Van der Sar’s gloves.
However, Foster - desperate for first team opportunities - was sold to Birmingham in the summer, while major question marks still hang over Kuszczak, leaving the untried Ben Amos as United's third choice option.
As a result, Ferguson is believed to be mulling a move for 20-year-old shot-stopper Hradecky, who currently plies his trade for Danish side Esbjerg but spent time on trial with the Red Devils during pre season.
United were sufficiently impressed to send scouts to watch Slovakian-born Hradecky in action for Finland's under-21s, and the young keeper is delighted to be linked with United.
"I was told [Manchester] United were keeping an eye on me when I played for Finland against Spain," he said in the Daily Star.
"It is unreal that they follow me."
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