Twenty-time Grand Slam champion Roger Federer and British number one Johanna Konta have both pulled out of this summer's Tokyo Olympics.
Federer, 39, has suffered a setback with an existing knee injury.
Konta, 30, has contracted Covid after withdrawing from Wimbledon when a member of her team tested positive and she was identified as a close contact.
The Swiss legend won doubles gold at Beijing 2008 and silver in 2012, losing the singles final to Andy Murray.
Federer, now ranked number nine in the world, had two knee surgeries in 2020.
In the last two years he has seen his Grand Slam tally equalled by Spain's Rafael Nadal at the 2020 French Open and most recently by Serbia's Novak Djokovic - who won a 20th major at Wimbledon 2021.