US gymnast Simone Biles dropped out of the women's team event after a single vault at the Tokyo Games on Tuesday while tennis superstar Naomi Osaka exited only days after lighting the Olympic flame.
The International Gymnastics Federation said Biles would play no further part in the team event, but said she would still receive a medal if the heavily favoured U.S. ended up on the podium.
"Simone has withdrawn from the team final competition due to a medical issue," said USA Gymnastics. "She will be assessed daily to determine medical clearance for future competitions."
Biles had been bidding for a record six gold medals in Tokyo.
Osaka, who lit the Olympic cauldron on Friday to open the Games after a one-year postponement, looked out of sorts and never settled into a rhythm as she lost 6-1 6-4 in the third round to Czech Marketa Vondrousova.
Osaka's departure left Japan without its best known global sporting figure in the Olympics, one whose multi-ethnic background contrasts with the image of an insular and male-dominated country that emerged in the run-up to the event.
"I think it's maybe because I haven't played in an Olympics before and for the first one to be here was a bit much," she said.
It was her first tournament since she pulled out of the French Open in May. The women's tennis tournament has now lost both of its top draw cards after Australia's world number one Ash Barty was beaten in the first round.
The Games are taking place under a state of emergency and without spectators, an unprecedented event in the history of the modern Olympics.
