The gifted 33-year-old returned to Brazil in January 2011 after a slump in his European career with two objectives - to win a place in his country's 2014 World Cup team and claim the club titles missing from his trophy cabinet.
On Wednesday, his Atletico Mineiro team will try to overturn a 2-0 first-leg deficit in the second leg of the Copa Libertadores final at home to Olimpia of Paraguay in Belo Horizonte.
Having inspired Barcelona to the Champions League crown in 2006, Ronaldinho hopes to join Brazilians Dida, Cafu and Roque Junior and Argentines Carlos Tevez, Walter Samuel and Juan Pablo Sorin as champions on the two continents.
The match is Ronaldinho's best chance to ensure his return to Brazilian football is not seen as a failure after a string of disappointments.
Flamengo brought the twice FIFA World Player of the Year back hoping the deal would have advantages on the field as well as marketing benefits off it, but the project sunk.
Ronaldinho spent a troubled 17 months at the Rio club, where he suffered a loss of form blamed on his party lifestyle.
In that time, Flamengo only won the minor Carioca (Rio) state championship and Ronaldinho left in May 2012 with the club owing him back wages.
For Brazil, with whom he won the World Cup in 2002 and also played at the 2006 finals, Ronaldinho appears to have lost his best chance of impressing coach Luiz Felipe Scolari and dropped out of the reckoning for next year's home finals.
Thanks to good club performances, especially in the Copa Libertadores, Ronaldinho earned a recall in April for a friendly against Chile at the Mineirao, the newly-refurbished stadium in Atletico's home city Belo Horizonte.
On top of a lacklustre performance in a 2-2 draw, Ronaldinho was not forgiven by disciplinarian Scolari for turning up late on the first day of training.
"You invite me to lunch at your home. I get to your house and you're not there. I wait and you, the host, are the last to arrive. The national team goes to the dining table and the last one to arrive? The host, that's not right," Brazilian Football Confederation (CBF) chief Jose Maria Marin said in a recent interview with Globo Network.
Ronaldinho was left out of Brazil's squad for the Confederations Cup last month and is unlikely to find a place in a team that won the title crushing world champions Spain in the final.
His talent, however, has never been in doubt and he hopes to shine in the Copa Libertadores final.
"Nothing is greater than the will to bring the title to the 'Galo'," Ronaldinho said on Twitter using Atletico's nickname 'Cockerel'.
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- Atletico Mineiro