RIO DE JANEIRO, Aug. 16 (Xinhua) -- The son of retired football great Ronaldinho has begun training with the youth academy of Brazilian Serie A club Cruzeiro.

Joao Mendes, 13, was approved in a trial last month without revealing his identity, Globo Esporte reported on Thursday.

Despite being free to train and play with the Belo Horizonte club's junior teams, Mendes cannot sign a professional contract until he is 14 due to Brazilian law.

A striker, Mendes said his father has taken a keen interest in his budding football career.

"He always supports me," the teenager told Radio Itatiaia. "It has always been my dream to be a footballer and it must be a dream for him too to have a son who plays."

Mendes is also understood to have sparked interest from Paris Saint-Germain, where his father played for two seasons before his 2003 move to Barcelona.

Ronaldinho, 38, announced his retirement in January after a career that included a World Cup trophy, a UEFA Champions League title, a Copa Libertadores and two FIFA World Player of the Year awards.