Jonny May has tested positive for Covid after arriving in Australia for England's three-Test Tour.
The England wing returned a positive test on Friday morning after reporting symptoms and will now spend seven days in self-isolation as required by Australian government regulations.
May, 32, could still be available for the opening Test against the Wallabies in Perth on Saturday, 2 July.
No other members of the England squad returned positive tests.
"Potentially he'll be available next Thursday to train, so we'll have a look to see what he's like," head coach Eddie Jones said in reference to May's availability for the series opener.
"He's experienced and he's showed in his first game back against the Barbarians that he's lacking game time and that he's got his best rugby ahead of him.
"We'll just monitor his situation and make an assessment closer to the day when he gets out."
May, who plays his club rugby for Gloucester, underwent knee surgery in January and marked his return to England's starting line-up with a try against Barbarians on Saturday.
With 35 tries, he is England's second highest try-scorer behind Rory Underwood.
The opening match against the Wallabies is followed by fixtures in Brisbane on 9 July and Sydney a week later.