Brazilian striker Hulk admits he has dreams he wants to fulfil as a player that he might not be able to achieve at Porto.
The highly-rated frontman is one of Europe's hottest properties, with heavyweights across England, Italy and Spain thought to have him on their wishlists.
Hulk was awarded a new five-year contract in the summer, while Porto also have a release clause in place of €100million (£87m).
But while the 25-year-old is happy in Portugal, he has hinted he could outgrow the club.
"Now I am happy at Porto because I am helping the club to success," he told Brazilian radio station Jovem Pan.
"The people are content with me and that is very important, but I also have dreams I want to fulfil as a footballer."
Hulk has not ruled out leaving Porto if an affluent club is willing to pay his release clause.
"In the world of football anything is possible," he added. "If a day arrives when an Arab sheik wants to pay my release clause I will leave the club.
"But who's to say the rich clubs are interested in me."