Michel Salgado has told talkSPORT that Real Madrid "would be crazy" to pay Tottenham a similar fee for Dele Alli as they paid for Gareth Bale.
Alli, 20, has been linked with a big-money move to join the European champions after a second impressive season in the Premier League with Spurs.
Bale left Tottenham as a 24-year-old who had twice been named as PFA Player of the Year, but Alli still has to prove if he is capable of performing regularly at the level that Real require, according to Salgado.
"Obviously they can pursue him because he's a great player, he's young, he's got ability and he's got pace, too," he said.