Numerous Russian sports stars, including their entire track and field squad, have been barred from the Games over the damaging doping scandal
The International Olympic Committee (IOC) should rule Thursday on how many Russian athletes will be allowed to compete in the Rio Games even though the sports tribunal is dealing with a 'record' number of appeals against doping bans.
Some 1.2 million tickets for Olympic events remained on sale ahead of Friday's opening ceremony, which has been overshadowed by accusations that Russia organized state-run doping.
And there were many empty seats when the women's football competition started on Wednesday with wins for hosts Brazil over China 3-0, World Cup holders United States 2-0 over New Zealand and highly ranked Germany over Zimbabwe 6-1.
Russia turned out in force to see their flag raised over the athletes' village in Rio on Wednesday.
Numerous Russian sports stars, including their entire track and field squad, have been barred from the Games over the damaging doping scandal.
But for tennis player Svetlana Kuznetsova, a two-time Grand Slam winner, it was vital for those allowed to compete to show their support and commitment by making their presence in the village -- and in front of the world's media -- highly visible.
"It's very sad that so many top athletes cannot be here with us because we're a big country," she said at the Russian welcome ceremony in the Olympic Village.
Russia has been at the center of a doping storm since an investigation for the World Anti-Doping Agency found the country's sports ministry organized doping on a huge scale.
A three-member Olympic panel is set to approve the final Russian contingent after the IOC ordered individual sports federations to draw up lists of athletes allowed to compete.
Federations have ruled out at least 119 of the 387 names proposed by the Russian Olympic Committee, according to an AFP count.
The Olympic leadership was "very close" to naming the final figure, IOC spokesman Mark Adams said. Draws for the boxing and rowing contests on Thursday increased pressure to announce the contingent.
The IOC had originally said that any athletes "implicated" in a report by Canadian lawyer Richard McLaren should be excluded by federations before appearing to ease its stance.
World Sailing said it had cancelled a ban against Russian 470 class contender Pavel Sozykin because of the "new guidance" it had received from the IOC on Monday.
The new statement "indicated that an athlete should not be considered as 'implicated' if the McLaren list does not refer to a prohibited substance which would have given rise to an anti-doping rules violation," the sailing federation said.
But dozens of would-be Russian Olympians remained in limbo as the Court of Arbitration for Sport (CAS) sorted through their appeals.
At least 11 of the 18 appeals launched at a special tribunal in Rio since July 26 involved Russian athletes banned because of the McLaren probe, the court said.
The tribunal in Rio had set "a new record of cases for one edition of the Olympic Games" even before the Rio event starts on Friday, CAS said in a statement.
The court had 11 cases in all to handle at the 2012 London Olympics.
CAS on Wednesday rejected a challenge by the Russian weightlifting federation against its suspension by the International Weightlifting Federation following the McLaren report.
That meant eight Russian lifters were banned from Rio. An appeal by 17 Russian rowers was also rejected.
Four Russian swimmers are among those still waiting to hear if their challenges have succeeded.
In the first Olympic action, Sweden's 1-0 win over South Africa in women's football started in a nearly empty Rio Olympic stadium.
The venue was closer to its 60,000 capacity for the second match later, when hosts Brazil, led by Marta, beat China 3-0.
Tickets remained available for many top events, including blue-ribbon athletics races such as the 100m final. Organizers said around 4.9 million tickets, about 80 percent of the total, had been sold.
The first matches of the men's football tournament will take place on Thursday, with Brazilian superstar Neymar spearheading the host nation's quest for a first-ever Olympic football gold medal -- the only international title to elude the five-time World Cup winners. Brazil take on South Africa after the opening match between Denmark and Iraq.
An IOC session meanwhile stepped up its trend of attracting the next generation of Olympic fans by announcing five new sports for the 2020 Games in Tokyo -- surfing, skateboarding, climbing, karate and baseball.
"This is really a milestone in the innovation of the Olympic program, which we can then experience in four years from now in Tokyo 2020," IOC president Thomas Bach said.