The 26-year-old has been widely linked with a move away from White Hart Lane throughout the summer, and was due to fly into the Spanish capital to complete the switch on Thursday.
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"It would be amazing [if Modric joined Madrid]. As the president of the Croatian football federation it is my wish and I hope that he ends up playing for Real Madrid," Suker told Marca.
"Having Luka at Real Madrid makes Croatian football more important and has a greater impact on everything.
"We will have to wait. This is football. Things are happening and it is normal for lots to be said, but I cannot say anything definite. His time will come. Luka is an amazing player."
Suker wore the Real Madrid jersey from 1996 until 1999, before leaving the club for Arsenal.