Andy Murray has tested positive for the coronavirus days before he was due to leave Britain for the Australian Open, a person with knowledge of the situation told The Associated Press on Thursday.The three-time Grand Slam champion is isolating at home near London and still hopes to compete in Australia when it is safe to travel, the person said.Murray has been given a wild-card entry into the first Grand Slam tournament of 2021.The Australian Open was delayed three weeks because of COVID-19 restrictions and is set to begin Feb.