Luton have signed former Peterborough and Brighton striker Craig Mackail-Smith on a two-year deal.
Norwich City have completed the signing of goalkeeper Jake Kean following his release from Blackburn Rovers.
Porto president Pinto da Costa insists he has not spoken to Hulk's agent about the striker's future, reiterating he will not be allowed to leave for less than his release clause.
A host of clubs have been linked with the Porto captain, with Chelsea, Real Madrid, Paris St Germain and most recently Zenit St Petersburg all said to be interested.
But da Costa remains defiant and is calm about Hulk's future at the club, insisting he will only sanction his exit if a club is willing to pay his release clause, which stands at a massive €100million.
"I didn't meet Hulk's agent. Hulk is a player with a buyout fee and if any club want him, they just need to pay that, they don't need to come here," said da Costa.
"Hulk will only leave if it interests both Porto and the player. But so far nothing happened to make me think we'll reach that point.
"Therefore, I expect that for this season Hulk will remain a Porto player."
Hulk's agent Teodoro Fonseca told Radio Renascenca that you can never rule out a move.
"Hulk has a contract, he likes FC Porto, but at the moment everything has a question mark," he said.
"We sometimes want a player to stay, but the conditions aren't the best. Sometimes clubs have to give up a right, a player, or a person to keep their structure. People come and go, but the clubs stay.
"Everything is possible in the world of football."