Ozzy Osbourne had surgery at Rose Medical Center Saturday night (July 28).
The 59-year-old was in town for Ozzfest 2007, which took place at Coors Amphitheatre on Saturday.
Kirk reports that Osbourne was complaining of leg pain for most of the day. After the show, Osbourne was taken to Rose where he underwent surgery on his leg for a blood clot.
Osbourne was expected to be released from the hospital on Sunday. Kirk says wife Sharon was not travelling with him.