Three-time Olympic champion Kohei Uchimura and double World Championship silver medallist Lilia Akhaimova have tested positive for coronavirus prior to next weekend’s team gymnastics event in Tokyo.
Uchimura is among the star names expected to compete at the one-off competition, which will feature athletes from China, Russia, the United States and the host nation Japan.
The event is scheduled to take place on November 8 at the Yoyogi National Gymnasium.
The competition will be one of the first international sporting events hosted by Japan since the coronavirus pandemic began.
International Gymnastics Federation (FIG) President Morinari Watanabe told reporters Uchimura has tested positive for coronavirus.
The two-time men’s Olympic all-around champion could still participate at the event, but would require negative tests on November 4 and 5.
Uchimura is currently in isolation at Japan’s national training centre and is asymptomatic.
"He has a very normal temperature of 36.3 C," Watanabe said, according to the Olympic Channel.
"He is in a very stable condition.
"At this point, it's just Uchimura.
"If we find out it's spread through the rest of the team, at that point, they might pull out.
"All the other teams have been isolated in their countries.
"It is an extremely disappointing result but we will continue to observe the situation.
"I know Uchimura was looking forward to this event so we want to go ahead with it however we can - for him, especially.
"If we had to cancel because of him, it would be unbearable for him, we want to avoid that at all costs."
Uchimura has struggled with shoulder injuries and last year failed to qualify for the finals of the Japan National Championships.
The six-time world all-around champion is expected to focus on winning the horizontal bar title at Tokyo 2020, having opted not to attempt to defend the all-around crown.
Athletes participating in the event are required to undergo "several" tests for coronavirus, both before arriving in Tokyo and during their stay in the Japanese capital.
The athletes will reportedly not face quarantine periods required for travellers to Japan, but will be quarantined for two weeks in their own country prior to the event.
Russia’s head coach Valentina Rodionenko has confirmed Akhaimova has been replaced for the event by Alexandra Shchekoldina, after she tested positive for coronavirus.
"Unfortunately, we are forced to make a replacement, instead of Akhaimova, Shchekoldina will fly to Tokyo," Rodionenko told the Russian state news agency TASS.
"Akhaimova passed the coronavirus test upon arrival at the base.
"She did not contact with anyone, as she had to be isolated before receiving the test results.
"According to our information, she is now feeling satisfactory.
“We hope that everything will be fine.”
Russia’s delegation, which includes Nikita Nagorny, Artur Dalaloyan, Dmitry Lankin, Alexei Rostov, Angelina Melnikova, Elena Gerasimova and Yana Vorona, are isolating at their Ozero Krugloye base before flying to Tokyo on November 5.
Gymnasts movements are expected to be limited to the venue and the team hotel on arrival.
This potentially could be repeated at the Tokyo 2020 Olympic Games next year.
Draft coronavirus countermeasures, produced by a three-party council, have suggested a "general principle" could be adopted to limit the range of athletes’ movement to facilities managed by Tokyo 2020, such as competition venues and training facilities.
The draft added measures such as encouraging athletes and officials to travel only via designated vehicles could be considered, although limited public transport use may be acceptable if unavoidable.
Apparatus in training halls and on the field of play will be cleaned and disinfected at the end of each session at the international team gymnastics event as part of COVID-19 protocols.
Spectators will be allowed into the venue but capacity will be restricted to 2,000.
Athletes are set to feature as part of two teams.
One will be named team friendship and the other named team solidarity.
Eight male and eight female gymnasts will be included on each team.