The Brazilian frontman has turned heads across Europe after making waves at the Estadio do Dragao, with the Blues thought to be frontrunners for his signature.
Chelsea boss Andre Villas-Boas knows what the 25-year-old is capable of after he helped inspire his Porto side's league, cup and Europa League Treble last season.
Hulk is contracted at the Portuguese giants until summer 2016 and has a €100million (£83.5m) get-out clause in his deal.
But the forward has not ruled out leaving if a suitable offer comes along and would not expect Porto to block a potential move.
Hulk said in the Daily Mirror: "We never know what is going to happen tomorrow.
"I have four-and-a-half years left on my Porto contract but, as I have always said, if some day something good for me and for the club appears, I think there will not be any problem and a deal will be reached.
"As long as it is amicable and good for everyone, I believe it will be concluded without any problem. If I do not leave, then that is fine."