Porto president Pinto da Costa will not budge from star striker Hulk's £83.5million buyout clause, but fears a club will eventually be prepared to meet the asking price.
The 25-year-old is one of Europe's hottest talents and Chelsea, Paris Saint Germain and wealthy Russian club Anzhi Makhachkala are all interested.
But Hulk is contracted with Porto until 2016 and no club has yet been prepared to meet his sky-high release clause.
Porto chief Da Costa hopes that remains the case, however, he is worried one club will in the future produce the money.
He is quoted as saying in the Sunday Star: "I hope that nobody meets Hulk's buyout clause, but I would not be surprised if someone pays it one day."
Chelsea have long been linked with Hulk and speculation has only increased with reports the Brazilian wants to be reunited with former Porto boss Andre Villas-Boas.