Bale has been heavily linked with a move to the Spanish capital with Madrid reportedly lining up a bid of £85million.
"The talk about Gareth Bale is not a surprise," Zidane, who is Madrid's sporting director, said. "It is impossible to have the season he just had and not be linked with the biggest clubs in Europe.
"If any club is going to tempt Spurs, then it will take big money – maybe even record-breaking money.
"There are four or five clubs at the moment who have the finances not to be put off by a record-breaking fee like that."