Ribeiro admits the race for the teenager is hotting up and hinted that his sizeable release clause would have to be met before Santos would consider selling.
"It is not just Madrid; a lot of other clubs in Europe have been calling us," Ribeiro told a press conference.
"It is no surprise - it would be strange if they didn't want him.
"If they pay the buy-out clause of 45million euros and the player wants to go, there is nothing we could do."
Nevertheless, the Santos chief hopes his side can hang on to the 19-year-old - especially if they win the Copa Libertadores.
"The clubs can talk to Neymar after the Libertadores, but I am sure that if we win the title, the reasons for Neymar to stay will be even stronger," he said.
"I know mind-blowing offers will arrive, but the player will benefit more if he keeps developing here."