Former Dallas Cowboys' running back Ron Springs has been hospitalized in a coma, more than seven months after receiving a kidney donated by ex-teammate Everson Walls. The Washington Redskins said Tuesday that cornerback Shawn Springs, son of the 50-year-old Springs, has left the team to be with his father. "[Shawn] has flown down there -- it's a very tough time for them because I think it's very, very serious," Redskins' coach Joe Gibbs said. It wasn't immediately clear what caused Ron Springs, who has diabetes, to lapse into a coma or when he was hospitalized.