Nuggets coach George Karl isn't likely to return to the club before the postseason, a source told ESPN.com's Chris Sheridan.
Karl has already missed eight games as he deals with neck and throat cancer. He is currently undergoing a rigorous six-week treatment program of radiation and chemotherapy.
Yahoo! Sports reported that the coach recently needed treatment for blood clots in his legs and lungs that surfaced while he was already undergoing treatment.
"He'll return -- we just don't really know the timing," one source told Yahoo! Sports. "It really depends on how he feels."
Karl's longtime girlfriend, Kim Van Deraa, discussed his recent health issues on his blog.
"On Sunday afternoon we had to rush him to the hospital. His leg was extremely swollen and he was having trouble breathing."