The Barca icon has confirmed he has returned a positive test for Covid-19 and is now self-isolating in Belo Horizonte.
Ronaldinho, who won 97 caps for Brazil between 1999 and 2013, posted a video to his Instagram story revealing his diagnosis.
The 40-year-old said he is asymptomatic and is self-isolating in Belo Horizonte, having arrived in the city on Saturday.
“I’ve been here in BH since yesterday, I came to participate in an event,” Ronaldinho said on Sunday.
“I took the test and tested positive for Covid. I’m fine, asymptomatic, but we’ll have to leave the event for later. Soon we will be there together. Big hug!”
It has been a turbulent year for Ronaldinho who, along with his brother Roberto Assis, was jailed in Paraguay in March after entering the country with fake passports .
The pair were moved to house arrest in a Paraguayan hotel in April after serving 32 days in prison, with their sentences ending in August.
“It was a hard blow, I never imagined that I would go through such a situation,” Ronaldinho said at the time.
“All my life I have sought to reach the highest professional level and bring joy to people with my football.”
The Brazilian became one of the most iconic figures in football history over the course of a playing career which lasted 17 years.
He won the Ballon d’Or in 2005 and was twice named FIFA World Player of the Year.
He told Serie A’s official website: “For me, Ronaldinho is the best player in history. I met him, I went to see a match at the Camp Nou and he was sitting next to me. It was a wonderful experience.
“Messi is incredible too, I like him very much. I played with him for six months and he is a nice person, a great player. The whole world knows about Messi.”