The promising youngster appeared to be on his way to Turin come December 2013 but his father has confirmed the door to La Liga remains open
The attacking starlet, 18, was initially expected to join the Serie A champions on a free transfer once his contract with Flamengo expires in December 2013, but he has now set his sights on a summer move instead as his club continue to leave him out of action.
"Juventus have shown serious interest in him and I know that there's an agreement in principal for a five-year deal," Bebeto told La Gazzetta dello Sport.
"However, Flamengo are not playing him any more because he's leaving in December when his contract expires. He can not just sit on the bench without playing until then.
"Juventus will have to pay €1 million to get him this summer. As soon as they pay, Mattheus is off to Turin.
"He has a lot of offers, though, and if Juventus do not wrap up things by May 10, we consider ourselves free to open talks with Real Madrid. They came in later than Juve, but have made a good offer."
Mattheus became something of a famous figure around the world only days after his birth following Bebeto's cradle-rocking celebration in Brazil's 3-2 win over Netherlands at the 1994 World Cup.