Real Madrid have confirmed David Alaba and Isco returned positive tests for COVID-19.
The duo are the latest Madrid players to contract the virus, taking the total to eight in the space of a week.
Los Blancos revealed last Wednesday that Luka Modric and Marcelo had gone into quarantine after routine testing determined they had the illness.
Gareth Bale, Marco Asensio, Rodrygo and Andriy Lunin then tested positive the following day, along with Carlo Ancelotti’s son and technical assistant Davide.
All are absent for Madrid’s scheduled trip to San Mames to face Athletic Bilbao on Wednesday.
Ancelotti’s side are six points clear at the top of LaLiga, having collected 43 points from their first 18 matches, but second-placed Sevilla can close the gap when they face Barcelona on Tuesday.