Three-time Olympic halfpipe gold medalist Shaun White's participation in a fifth Winter Games at Beijing remained in limbo Sunday after the snowboard star withdrew from the World Cup event in Mammoth Mountain, California.
White, 35, entered the event despite battling Covid-19 in late December.
The American, who was born with a heart defect that required two major surgeries before his first birthday, said his symptoms were relatively mild.
But he noted that with his health history, which also includes childhood asthma, "anything to do with lungs and respiratory is not so great."
In the event, White picked up an ankle injury and withdrew from Saturday night's finals -- although he can still be selected for the US team for Beijing, where Saturday's top finishers Ayumu Hirano and Ruka Hirano of Japan will likely be the men to beat.
White has been an ever-present in the US Winter Olympic team since he won his first gold in Turin in 2006 as a 19-year-old.
He retained his title at the 2010 Vancouver Winter Games, then snatched a third gold with a dramatic final-run triumph at the 2018 Pyeongchang Olympics.
White said in December that he expected the Beijing Games to be his last.
"I haven't really said this too much, so it's going to feel weird coming out of my mouth, but this is I think my last run," he said on NBC television's Today program.