Britain's former world number one Andy Murray has pulled out of next week's ATP event in Delray Beach - but not because of injury concerns.
Murray had accepted a wildcard to start his 2021 season at the Florida event.
But he will not to travel to the United States, appearing concerned it could stop him from playing at the Australian Open, which starts on 8 February.
Players will have to pass a series of Covid tests during a 14-day quarantine in Melbourne before the Grand Slam.
Murray's appearance there comes two years after he played what he feared would be his final match as a professional at Melbourne Park.