The 2009 world downhill champion isn't racing in the season-opening World Cup downhill Saturday or in Sunday's super-G at Lake Louise, Alta.
Kucera was the first Canadian man to stand atop the podium at Lake Louise when he won the super-G in 2006. He also won a silver in the discipline in 2008.
The Calgarian is dealing with the lingering symptoms of vestibular neuritis, an inner ear condition causing dizziness and nausea. It struck suddenly at a training camp in Chile in September.
"I literally went to bed with a cold and woke up and went to turn off my phone alarm and got full dizzy spins and the whole nine yards," Kucera says.
"The easiest way to describe it is post-concussion. It's sensitivity to motion. I get nauseated and stuff and a little fog comes over me and I can't focus on skiing gates."
That's a problem when Kucera needs to navigate terrain and gates at 130 kilometres per hour. The 29-year-old has been free skiing this week, but Kucera isn't at a point where he could race and be competitive.
"This is a place I love to race and it's not even just here," Kucera said. "It's any race when they're going to be on. It's not like when you have a broken leg and you're so out, it's unrealistic to even think you can do it.
"With this, you almost feel like you're so close, but you're just not there. It'll be frustrating in that regard."
Erik Guay of Mont-Tremblant, Que., Vancouver's Manny Osborne-Paradis and Jan Hudec of Calgary are Canada's top medal hopefuls at Lake Louise this weekend.
Between those three and Kucera is a litany of back and knee injuries. Hudec leads the way with seven knee surgeries. Kucera broke his leg at Lake Louise in 2009 and didn't race the next three seasons.
The skiers accept these as the occupational hazards of their sport, but Kucera's vertigo seems strange and random to them.
"It's a bummer Johnny's not feeling up to it yet, but hopefully that will settle down and he'll be back on the snow soon," Guay said. "It is a weird one. I'd never heard of it. He said he looked online for a long time and he's only found two cases of it with athletes.
"He said the two athletes he found was a Major League Baseball player and a professional tennis player. If you fall down in those sports, it's not a big deal, but when you're going 140 and you get dizzy, there's some serious consequences. I wouldn't risk it too much."
Norway's Aksel Lund Svindal won Friday's final downhill training run that was shortened to the super-G course because of poor visibility at the top of the mountain.
While Lake Louise is nicknamed "Lake Lindsey" because of Lindsey Vonn's multiple wins in the women's races, Svindal is approaching that domination on the men's side. Svindal has won five times at the Alberta resort, including victories last year in both downhill and super-G.
Georg Streitberger of Austria was second and Bode Miller of the U.S. was third Friday.
Osborne-Paradis was the top Canadian in 25th and Guay 26th. Fogged goggles and a missed gate made Hudec's run adventurous, although he did get to the bottom.
"I went on a road trip and almost didn't come back and ran out of gas and didn't put windshield wiper fluid in the tank. But I still made it," Hudec said. "I definitely took the scenic route."
Guay was fastest in the first training run with Osborne-Paradis and Hudec also in the top 10, so the Canadians feel confident and relatively healthy heading into their home race.
"We have guys who are definitely in contention of getting a podium here," Osborne-Paradis said. "We need to push it. Hopefully it happens, but if it doesn't, there's a race every weekend."
The timing of Kucera's malady isn't good. Breaking his leg in the super-G in 2009 kept him from racing at the 2010 Winter Olympics as well as the next three seasons.
He returned to the World Cup last winter with the intent of building a base of racing under him again. The men's speed team has depth this season and there will be internal competition for the four downhill spots on the 2014 Olympic team.
Hudec, Osborne-Paradis, Guay, Ben Thomsen of Whistler, B.C., and Kucera, if he can get back to racing, are the forerunners for the Olympic team.
But that group will also get competition from brothers Morgan and Conrad Pridy and Robbie Dixon of Whistler, Dustin Cook of Lac Sainte-Marie, Que., and Jeffrey Frisch of Mont-Tremblant.
All will race Saturday except for Cook, who declined his spot to concentrate on Sunday's super-G, and Dixon, who didn't qualify out of training.
Hudec, Osborne-Paradis, Guay and Thomsen have met half the criteria for Olympic selection, as those four each achieved a top-12 result last season. Kucera needs a pair of top-12 finishes or one top-five this season to meet the standard.
But all he can do for now is wait until his symptoms disappear, which is not unlike having a concussion.
"Sometimes you kind of get dealt the cards you get out of nowhere and a weird one," Kucera says. "The good thing about it is it's nothing super-serious where my health is really at risk long term.
"At the end of the day, it's a bummer and my career might suffer, but it's a good thing I'm not here fighting for my life or something really crazy. There's other crazy health cards out there that can really get you."