"I want you to get to know Juve," Melo wrote. "For those who don't know Juve, they are the team with the most fans in Italy.
"Almost 30 per cent of Italians support this historic club, which is the one that has won more League titles than anyone.
"I am very proud to wear this shirt. We have a modern training ground with seven pitches and with all the infrastructure an athlete needs."