Japanese officials expressed unease after the Court of Arbitration for Sport on Thursday overturned lifetime Olympic bans on 28 Russian athletes.
Eight days before the start of the Pyeongchang Olympics in South Korea, the CAS upheld 11 lifetime bans but said the International Olympic Committee lacked sufficient evidence to ban 28.
"The Olympics are getting messed up," one Japanese Olympic Committee official said.
Although the bans have been removed, the 28 will not be able to attend the games in South Korea. Since the Russian national Olympic committee is currently suspended, the nation's athletes can only compete by invitation of the IOC, the body said in a statement.
Among the athletes who the CAS ruled in favor of are a number of top-class cross-country skiers.
"Can we accept the performance of such athletes when they compete," asked Katsuhito Ebisawa, the Ski Association of Japan's cross-country director. "I'm worried our sport is going to be stuck with a doping label."
Takashi Kawakami, the director of speedskating for the Japan Skating Federation, was no less stunned.
"I'm disappointed by this decision," he said. "I won't know who to trust. I want the Olympics, an engine of dreams and ambition, to be free of suspicion."