Star forwards Cristiano Ronaldo and Gareth Bale were absent from Real Madrid's final training session for the trip to Espanyol on Sunday.
Three-time Ballon d'Or winner Ronaldo, who only returned to action from a knee injury in last weekend's 5-2 win over Osasuna, was laid low by flu.
Wales international Bale was substituted midway through the second half of Wednesday's last-gasp 2-1 Champions League comeback win over Sporting CP and is suffering from soreness in his hip.
Madrid face Espanyol at Estadio Cornella-El Prat on Sunday, where they will look to maintain their 100 per cent start to the season.
Reports in Madrid on Saturday suggested head coach Zinedine Zidane was set to rotate his Madrid line-up on the back of their midweek exertions.