Ronaldinho will represent his former club Fluminense at an exhibition tournament in the US next month, the Brazilian club confirmed on Thursday.
The 35-year-old left Fluminense by mutual consent in October after failing to score or provide an assist in nine matches for the Rio de Janeiro outfit, Xinhua news agency reported.
"It wasn't a mistake, it was an opportunity," Fluminense president Peter Siemsen told reporters.
"We were frustrated and he was too. It was something we tried and in life that's what you do. When there are opportunities we aren't afraid to take them. We left on good terms."
It is understood that Ronaldinho's return for the Florida Cup honours a clause written into the attacker's contract when he joined Fluminense in July.
Fluminense see his participation as a unique opportunity to promote the club's brand.
The Brazilian side will be among eight teams to compete in the tournament along with Internacional, Atletico Mineiro, Corinthians, Schalke 04, Bayer Leverkusen, Shakhtar Donetsk and Santa Fe (Colombia).