The 22-year-old Portugal international is under contract with the Sportinguistas until 2018, but has a release clause of €45million.
Manchester United are known to have been keeping close tabs on the player, and were believed to be leading the chase for his signature.
However, talk of a new and improved contract in Lisbon could persuade Carvalho to stay - a result that the defensive midfielder seems to be open to.
"My future will not be a problem," Carvalho told SIC.
"I am joining the national team with my future resolved.
"I am a Sporting Lisbon player until June 2018 and when I return from the national team, I'll be back training at Lisbon.
"Everything else is just speculation."
Carvalho has been included in Paulo Bento's Portugal squad for the upcoming World Cup in Brazil, and admitted his surprise at being called up, despite his fine form.
"It was very good news; I was not expecting to be summoned, despite knowing it had a chance of being true," he added.
"I dreamed that someday I would be player of the national team and with the good work done throughout the season, it became easier."