LOUISVILLE, Ky. — Muhammad Ali was back in the hospital for follow-up care related to a severe urinary tract infection, his second stint in the hospital in the last four weeks.

The three-time former heavyweight champion was admitted to an undisclosed hospital earlier this week, Ali family spokesman Bob Gunnell said Thursday. Ali was in stable condition.

Ali was hospitalized on Dec. 20 with what was initially believed to be a mild case of pneumonia. Doctors later determined Ali was suffering from a urinary tract infection, not pneumonia, Gunnell said.

LOS ANGELES — Austin Rivers joined the Los Angeles Clippers to play for Doc Rivers in the first father-son, player-coach combination in NBA history.The Clippers acquired Austin Rivers from the Boston Celtics in a deal that included the Phoenix Suns.Coby Karl was briefly a member of the Denver Nuggets in 2010 under father-coach George Karl, but didn't play during a stint that coincided with his father being on leave for treatment of throat cancer.

GLENDALE, Ariz. — Houston defensive end J.J. Watt, Pittsburgh wide receiver Antonio Brown, Cleveland cornerback Joe Haden and Dallas running back DeMarco Murray will serve as Pro Bowl captains.