Real Madrid have said goalkeeper Thibaut Courtois did not suffer an anxiety attack at half-time during their Champions League draw with Club Brugge.
Courtois' first-half performance was criticised after he conceded two goals to Emmanuel Bonaventure and he was substituted at the break.
It has since been reported that the former Chelsea goalkeeper had anxiety-related problems and had to be replaced by Alphonse Areola.
In a statement on Friday, Real Madrid said: "Our player has never been diagnosed with an alleged anxiety picture and therefore, that information is absolutely false.
"Thibaut Courtois has been diagnosed and treated for acute gastroenteritis with dehydration and electrolyte imbalance, which made it impossible to end last Tuesday's game against Brugge.
"The player currently responds favourably to the treatment."
Madrid are top of La Liga and remain unbeaten after their first seven league matches, but have struggled in the Champions League after losing their opening group game 3-0 away at Paris Saint-Germain.
Second-half goals from Sergio Ramos and Casemiro earned a 2-2 draw with Club Brugge at the Bernabeu.