The Brazilian forward flourished under Andre Villas-Boas at Estadio do Dragao and the Portuguese manager has hinted at his desire to add the 25-year-old to his squad at Stamford Bridge.
Villas-Boas led Porto to three trophies last season, with Hulk's 36 goals in all competitions playing a signifcant part in the team's success.
And Hulk has identified Chelsea as his preferred destination should Porto agree to allow to him to leave.
"I've said it before, we would not sell Hulk and therefore Chelsea must activate his contract," Da Costa insisted.
"We know there is lots of interest from Europe, but the player has told me privately Chelsea is his preferred destination."
Hulk has bagged seven goals in 15 league games for Porto this season. He arrived in Portugal in 2008 from Japanese side Tokyo Verdy.
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