Thibaut Courtois has been released from international duty and will return to Real Madrid, the Royal Belgian Football Association (RBFA) has confirmed.
No reason for Courtois' departure from their training camp was given in the statement confirming the news published on Belgium's official Twitter account.
It was reported in the Belgian media this week the 28-year-old goalkeeper had tested positive for coronavirus, but Roberto Martinez insisted it was "wrong information" and he had been cleared to play.
Martinez said on Thursday: "Thibaut Courtois is available to work. The professor and the medical committee has given us the negative in terms of the COVID virus and that [the rumours] really upsets me.
"I didn't expect that sort of trying to chase the news and if you've got some sort of rumours, it's very easy to speak with [media manager] Stefan van Loock and try to see if it's right and wrong.
"This is an issue of confidentiality first and foremost in medical terms, and secondly it's wrong information."
Belgium are scheduled to face Denmark in the Nations League on Saturday, before a home game against Iceland on Tuesday.