"It was an incredibly difficult decision to stay home from the Olympics," said Guay. "Despite everything we did, I do not feel I can attend the Games and be at a competitive performance level that I would be proud representing Canada with.
"I am so thankful for the support behind me. My family, fans and sponsors have been incredible to me and I cannot thank all of them enough for their never-ending backing. I will be cheering on all of Team Canada from home, especially my teammates at Alpine Canada."
The three-time Olympian from Montreal is Canada's most accomplished alpine ski racer, having reached the World Cup podium on 25 occasions and has three world championship medals.
The decision means Guay has skied his last Olympic race. He confirmed on a conference call that he has no plans to make a run to return at the 2022 Games in Beijing.
"I can definitely say I will not be there," Guay said. "This was my final shot at the Olympic Games. As far as whether I'll continue next year or not, that's still a question mark. I think the remainder of the season is probably going to be finished for me."
Guay said that back issues of varying degrees have plagued him throughout the season. Guay added he knew that things weren't progressing the way he hoped, but he wanted to wait until the last minute before making the final call on the Olympics.
"When I'm free-skiing it's not too bad, but the moment that I get into a downhill position — in my tuck — I have pretty severe pain in my back," Guay said. "It catches me within four or five turns."