The Anthony speculation has been just part of the uncertainty that had buffeted the Nuggets this off-season. Whether Karl would be healthy enough to coach was a question mark, too.  The Nuggets, winners of 50 or more games three years in a row, were in the playoffs again last spring while Karl was going through cancer treatment. There was talk that Karl might return to the team after the first round.  Not a chance. He was being nourished through a feeding tube because throat cancer had made it so difficult to swallow. He slept with oxygen pumping into his lungs. A machine suctioned mucus from his mouth. He was on his way to losing 17 percent of his weight, and his neck was red and raw from a rash caused by the cancer treatment.  “It’s a hellacious experience,” Karl said during a recent interview at Pepsi Center. “One thing I’ve told all the doctors: You did not do a very good job of telling me how hard this is going to be.”  Karl had surgery for prostate cancer in 2005. His son, Coby, had thyroid cancer in 2006 and 2007. Now the 59-year-old Karl — slimmer, a bit weaker-voiced and unable to taste much, including the cans of Ensure he drinks for nourishment — is about to embark on his seventh season with the Nuggets.  Doctors have cleared him to coach, and training camp begins Tuesday. Karl and several other players are working on the last year of their contracts, too, and there is a sense that the Nuggets are balanced precariously between contending and rebuilding.  Their longtime owner, Stan Kroenke, as a condition to his becoming majority owner of the N.F.L.’s St. Louis Rams, handed operational control of the Nuggets and the N.H.L.’s Colorado Avalanche to his 30-year-old son, Josh, this summer.  The Nuggets dismissed Mark Warkentien, the vice president for basketball operations who was the N.B.A.’s executive of the year in 2008-9, and replaced him in late August with Masai Ujiri, 38, who served as assistant general manager with Toronto. With training camp approaching, there were still “discussions,” Karl said, about who would serve as his assistants. The big men Kenyon Martin and Chris Andersen will probably miss the start of the season while recovering from knee surgery.  A team that Karl says can be better than it was last season — 53 victories, a Northwest Division title and a first-round playoff exit — seems in flux. Karl shrugged most of it away.  “But rebuilding or restructuring the team — that would be disappointing to hear,” he said. “Especially this year for me.”  Karl said he thought he might be leading a championship team last year when he felt something on his neck.  “I thought the lump was just a fatty thing, being a fat guy,” he said.  It was squamous cell carcinoma in the throat, similar to what the actor Michael Douglas was recently found to have. When Karl made his diagnosis public Feb. 16, he casually said he hoped to coach again that season.  “I was like, ‘There is no way he is going to do that,’ ” Jim Boylan, a Milwaukee Bucks assistant, said Tuesday. “It isn’t going to happen.”  Boylan had a similar form of cancer, at the base of his tongue, in 2009. His treatment was similar, too.  “The first 10 to 14 days are O.K.,” Boylan said. “Then, suddenly, it’s like someone hits a switch. All the side effects kick in.”  Karl underwent 35 days of radiation treatment accompanied by weekly doses of Erbitux, a cancer-fighting drug.  His neck and throat were burned and blistered. He could not eat. His mouth was impossibly dry and slimy. (“ ‘I can’t wait until I’m not going to have garbage mouth’ — that’s how he’d say it,” said Kim Van Deraa, whom Karl calls his life partner.)  “When you’re not breathing the same way that you’ve breathed for 58, 59 years, you have a little anxiety about sleeping,” Karl said. “You’re afraid you might choke.”  Karl saw the expressions of shock that visitors tried to suppress. He saw the worry on the faces of his children. Kaci, his 6-year-old daughter with Van Deraa, “looked at me a little like a monster.”  But most did not know what Karl was going through — “They didn’t see the daily experiences,” Van Deraa said — which led to premature presumptions about his return.  “It’s actually after the treatment that it gets worse,” Karl said. “I was done with treatment the first week of April, but probably the hardest part of my recovery was the six weeks after that.”  Doctors and people like Boylan assured him his condition would improve drastically. It has. Karl began daily trips to the office in August and, after tests a few week ago, his doctors gave their blessing for him to coach. Besides his habit of licking his lips and swirling his tongue in his dry mouth, he shows no signs of the ordeal.  “Food doesn’t taste the same,” Karl said. “I love food. For some reason, I had an Oreo milkshake the other day. That kind of woke my buds up — ‘Hmm, that’s pretty good.’ ”  He may do less shouting when practices start, to save his tender throat, and delegate more to his assistants. When the Nuggets have back-to-back games, he may skip the overnight flight and catch up with the team the next day. But Karl said he did not consider quitting, even if he had every excuse to do so.  “I don’t think there’s a curveball you can throw at me that I haven’t seen before,” Karl said. “I kind of have a year to swing and see what happens.”  A version of this article appears in print on September 26, 2010, on Page SP1 of the New York edition with the headline: Karl Returns to Nuggets With His Resolve Intact. Order Reprints| Today's Paper|Subscribe
George Karl, 59, is returning for his seventh season as the coach of the Nuggets. But it is not clear if the team will be contending or rebuilding.