( CNN ) The family of boxing legend Muhammad Ali hopes he will be home from the hospital in time for his 73rd birthday on Saturday . Ali , who has Parkinson 's disease , has been in an undisclosed hospital this week getting follow-up care for a urinary tract infection , a spokesman for the family said Thursday . Bob Gunnell said Ali is in stable condition and doctors indicated he would be released Friday . Ali was initially released from the hospital on January 7 after an 18-day stay . Born Cassius Clay , the fighter won an Olympic gold medal as a light-heavyweight at 18 . In 1964 , he became world heavyweight champion in an upset victory against Sonny Liston . Shortly thereafter , he changed his name to Muhammad Ali to reflect his conversion to Islam . The boxer was also known for his protest against the Vietnam War and refusal to be drafted into service because of his religious conviction . He won his first 31 fights before losing to Joe Frazier in a 1971 fight hailed by some boxing experts as one of the greatest matches of all time . He retired from boxing in 1981 as a four-time heavyweight champion and announced his diagnosis with Parkinson 's disease three years later .
Joe Frazier is getting follow-up care for a urinary tract infection , a spokesman says . He is expected to be released on Friday , 18 days before his 73rd birthday . The boxing legend was hospitalized for Friday until he was originally released a day .