The 25-year-old is linked to both the Saints and West Ham United, per A Bola in Portugal.
The forward, who scored eight goals in 31 games for Boavista in the league last term, can play down the middle and on both wings.
The report also claims Watford and Brighton have an interest in the player.
He said about his future, per translated quotes from Mais Futebol: "I finished the season well at Boavista, that's why there are teams interested in me.
"At the right time it will be official and everyone will know.
"We want it to be something good, my goal is to continue to evolve and look for bigger teams, I never hid it.
"I like the English league. For now, these are just rumours, when there is something concrete it will soon be gone.
"If I have the opportunity to go to England I'll take it, but for now there's nothing."