Real Madrid released a club statement denying that Thibaut Courtois is suffering from anxiety.
Courtois was removed at halftime during their Champions League clash against Club Brugge due to illness.
Courtois will also miss Real Madrid's match against Granada this weekend.
The keeper has also lost over six pounds recently.
"In relation to certain information about our player Thibaut Courtois. Real Madrid want to state the following: 1. Our player has never been diagnosed with anxiety and that information is absolutely false. 2. Courtois has been diagnosed and treated for gastroenteritis with dehydration and an electrolyte imbalance, which made it impossible for him to finish Tuesday's game against Brugge. 3. The player is responding well to the treatment," said Real Madrid.