Two-time FIFA world player of the year Ronaldinho could miss December's Club World Cup due to an injury.
The 33-year-old tore the muscle in his left groin while training for Brazilian outfit Atletico Mineiro Friday, reports Xinhua.
"After clinical exams and a scan we confirmed he had totally ruptured the adductor muscle of his left thigh," Atletico's doctor Rodrigo Lasmar told the club's official website.
The Club World Cup, featuring each of FIFA's six continental club champions plus the host nation's league winners, will be played in Morocco from Dec 11-21.
Atletico Mineiro earned the right to play in the tournament by defeating Paraguay's Olimpia in the Copa Libertadores final in July. They are favourites to meet European champions Bayern Munich in the final.