According to a report by the BBC, Edwin van der Sar has been admitted to intensive care after suffering a bleed in his brain.
The 52-year-old is reportedly receiving treatment at a hospital in Croatia, where he is on holiday.
Ajax, where Edwin van der Sar was last seen, said his condition was stable.
Previously, Edwin van der Sar was the CEO of Ajax.
He and Ajax have a special relationship because he previously played with the Dutch national team.
But last May, Van der Sar resigned after Ajax finished third in the standings.
By finishing third, Ajax failed to qualify for the Champions League next season.
This is the first time that Ajax has failed to play in the Champions League, and the last time since 2009.
“Everyone at Ajax wishes Edwin a speedy recovery,” the Ajax statement said.
“We've been thinking of you ”
After that he joined the board of directors of Ajax in 2012 until he was appointed CEO of the club in 2016.
In a statement, Manchester United also wished the former goalkeeper a speedy recovery.
“Sending all our love and strength to you, Edwin.”
While his former teammate, Rio Ferdinand also gave van der Sar support.
Rio Ferdinand wrote on Twitter, “Ed is a warrior. Our thoughts are with the Van der Sar family.”