The 27-year-old Columbian has been linked with a move to White Hart Lane as Andre Villas-Boas looks to add to his attacking options, with Emmanuel Adebayor no longer in the picture at the club.
Villas-Boas is not alone in looking at the striker as Chelsea's Jose Mourinho, Liverpool's Brendan Rodgers and Napoli's Rafael Benitez are also said to be keen to land the player.
Martinez made it clear that he is keen to test himself at a higher level before he gets too old.
"The years are passing and one day I hope to make a good transfer," Martinez said.
"It clearly depends on Porto, a club that sells its players so well. Leaving or staying depends on Porto but I will only go if there is something concrete."