United have been strongly linked with the 24-year-old, who was Player of the Year in Brazil last season.
"[Any club wanting Everton Ribeiro] will need to offer a lot of money to sign him. I can't ensure he will be at the club his whole life, but [I'll only sell him] if an offer reaches what I want," Cruzeiro's president Gilvan de Pinho Tavares told Lancenet.
"I am good at keeping players at the club, I kept Walter Montillo a whole season, so the fans can be calm as it won't be any offer that will be enough to sign Everton Ribeiro."
The club's director of football Alexandre Mattos added: "There is nothing official, he was sounded out and there were some talks with Ukraine and Qatar, but nothing official.
"And that's not only regarding Everton Ribeiro, but also regarding the other players."