One of the world's greatest champions, Muhammad Ali, is back in the news after being admitted to an undisclosed hospital Saturday with pneumonia, according to reports. According to Bob Gunnell, Ali's spokesman, the former three-time heavyweight champion is in a stable condition. "Ali, who suffers from Parkinson's disease, is being treated by his team of doctors and is in stable condition,†Gunnell said in a statement. Physicians caught early, and Ali, 72, is not expected to be in the hospital for a lengthy period of time. "The prognosis is good,†Mr. Gunnell said. Ultimately, he gave no other details and asked that the privacy of Ali's family be respected. Ali recently posted his first selfie photo on Instagram during the Louisville Cardinals rout against the Kentucky Wildcats in college football. Before that, he appeared in public at a ceremony in September in his hometown of Louisville for the Muhammad Ali Humanitarian Awards. Muhammad Ali was born Cassius Clay and won an Olympic gold medal as a light-heavyweight at age 18. In 1964, he became world heavyweight champion in an upset victory against then champion Sonny Liston, according to Ali's official website. The popular pugilist changed his name to Muhammad Ali to reflect his conversion to Islam. The Greatest endeared himself to the entire world when he protested the war in Vietnam by refusing to be drafted into service out of religious conviction. He retired from boxing in 1981 and announced his diagnosis with Parkinson's disease three years later. On the following pages, a few notable people offer their thoughts and prayers about Ali's condition. You can leave yours in the comments section below! SOURCE: BBC Best wishes to the great Muhammed Ali currently in hospital with pneumonia Still a fantastic icon. – Duncan Bannatyne (@DuncanBannatyne) December 21, 2014 Wishing the legend Muhammad Ali a speedy recovery who is in hospital with a mild case of pneumonia #boxing #legend – BetVictor (@BetVictor) December 21, 2014 Best wishes to Muhammad Ali, who is in hospital with what is said to be a mild case of pneumonia – Ian Abrahams (Moose) (@BroadcastMoose) December 21, 2014 Sending prayers... ðŸ™RT @AP: BREAKING: Spokesman: Muhammad Ali in hospital with 'mild' pneumonia; prognosis good, short stay expected. – Mara Brock Akil (@MaraBrockAkil) December 21, 2014 Prayers go out to the greatest of all time. Muhammad Ali is battling pneumonia in the hospital. Prayers! – Whisker Biscuit (@L1C4Nation) December 21, 2014