Muhammad Ali
Muhammad Ali has been hospitalised again after a complicationReuters

Boxing legend Muhammad Ali has been hospitalised for follow-up care for a urinary tract infection for which he received treatment in recent weeks, and he is expected to be released in a day, a spokesman said on Thursday.

Ali, who expects to celebrate his 73rd on Saturday with his family, was admitted to the hospital earlier this week and was in stable condition, family spokesman Bob Gunnell said.

"There were further issues with the earlier diagnosis of a urinary tract infection," he said.

Gunnell declined to disclose the name or location of the hospital or what day he checked in, but he said Ali would be released from the facility on Friday.

The three-time world heavyweight champion was admitted to an undisclosed hospital on 20 December with what was believed to be a mild case of pneumonia.

Doctors later determined he was actually suffering from a severe urinary tract infection, and Gunnell disclosed on 7 January that Ali had been released.

Ali, who is nicknamed "The Greatest," was diagnosed with Parkinson's disease about three years after he retired from boxing in 1981 with a 56-5 record.