The former Barcelona midfielder trained on Friday and coach Cuca told reporters he could return to action against Fluminense in Brazil's Serie A on December 1.
"We hope to use him before the league season ends, maybe in the last or second from last match," Cuca said at news conference at the team's Belo Horizonte base.
"We don't have an exact date but his recuperation is going very well."
Ronaldinho tore a muscle in his left thigh in September and it was feared he would miss the tournament in North Africa.
Libertadores Cup holders Atletico Mineiro face as yet unknown opponents in the semi-finals on December 18 and expect to meet Champions League winners Bayern Munich in the final three days later.