Naomi Osaka said she felt “really scared” after watching opponent Daria Saville collapse with a knee injury just seven minutes into their Pan Pacific Open match in Tokyo on Tuesday.
Australian Saville retired from their first-round encounter after hurting her left knee hitting a cross-court forehand in the second game of the match.
The world number 55 yelled out “my knee” before dropping to the ground in agony, and Osaka rushed over to her side of the court to check on her opponent.
Saville, 28, retired from the match after several minutes of treatment and Osaka, who has struggled with injury herself this year, said she felt “really sad” for her opponent.
“I thought that she was just yelling because she thought her forehand was out, then I realised that she was yelling because she was in pain,” said the former world number one, who is aiming to break a slump in form this week in Tokyo.