Three-time heavyweight champion and boxing legend Muhammad Ali was reportedly admitted to a hospital with a mild case of pneumonia, according to ESPN.

Ali had a short hospital stay, his spokesman said Saturday night.

Bob Gunnell, Ali's spokesman, said in a statement, "He was admitted earlier this morning and because the pneumonia was caught early, his prognosis is good with a short hospital stay expected."

Gunnell said that he was in stable condition.

Radar Online reported that Ali had stopped breathing on Friday night and was revived by emergency responders. His daughters flew to Phoenix to be by his side, Radar Online reported, according to an unnamed source.

Ali has been battling Parkinson's disease, which has made his public appearances scarce in recent years, ESPN reported.

Radar Online reported his health has deteriorated in the past year and he has lost the ability to speak.

His family is worried about the former champ's health and hopes he will make it to his 73rd birthday on Jan. 17.

The current situation which has landed him in the hospital is reportedly mild, according to ESPN.

His most recent appearance was in September, for a ceremony in his hometown of Louisville for the Muhammad Ali Humanitarian Awards.

Although he did not speak at the ceremony, Ali did pose for photos.

One of the winners, former NFL great Jim Brown, told ESPN that, during the photo session, he had leaned over to Ali and whispered, "You're the greatest of all time."

Ali retired from boxing after about two decades in 1981 and then devoted his time to social causes, ESPN reported. He has traveled around the world for humanitarian missions.

Ali spent time during his travels mingling with a range of individuals -- from the masses to world leaders.

A center bearing his name, and dedicated to his humanitarian causes and boxing career, is located in his hometown.

In 2005, President George W. Bush awarded Ali the Presidential Medal of Freedom.