Joao Mendes,14, will line-up with Cruzerio's youth teams after impressing during a trial to earn a multi-year deal with the club.
However, the Brazilian club didn't know the talented forward's legendary lineage until after they signed him as Mendes didn't reveal Ronaldinho was his father until after he put pen to paper.
"Although he was the son of Ronaldinho, Mendes performed a test in the club without the knowledge of kinship," a club statement said.
"With his own talent, the young attacker was approved and, only when he was already in the club, was eventually revealed the name of his famous father."
Amarildo RIbeiro, Cruzerio's head of youth teams, said Mendes has a very bright future in the game.
"He's a promising player with an interesting style," Ribeiro said.
"I believe it won't take too long for him to go pro.
"He's really athletic and has great technique. He can play both the striker and center attacking midfielder positions. He's tall, but he can run. He can put it in the back of the net too."
Ronaldinho first broke through as a star at Brazilian club Gremio before earning a move to PSG in 2001.
However it was the 2002 World Cup where the silky skilled attacker really caught the world's attention when he played a key role in Brazil's tournament win.
After turning down a blockbuster move to Manchester United, Ronaldinho joined Barcelona where he would go on to win the Champions League.
Moves to AC Milan, Flamengo, Atletico Mineiro, Queretaro and Fluminense wrapped up his career before he announcing the end to his playing days in 2015.
