Barcelona forward Lionel Messi and goalkeeper Victor Valdes are unavailable for the King's Cup last-16 first leg at home to Osasuna on Wednesday because of flu and fever, the La Liga club said on their website (www.fcbarcelona.es).
Coach Pep Guardiola may in any case have rested Messi as the World Player of the Year arrived back from his native Argentina on Monday while Valdes was unlikely to have featured as number two keeper Jose Manuel Pinto normally keeps goal in the Cup.
Barca, who lost 1-0 to Real Madrid in last year's final, will meet Real in the quarter-finals if they get past Osasuna and the Madrid side dispose of Malaga, whom they beat 3-2 in Tuesday's first leg at the Bernabeu.
The second legs are scheduled for next week.
Injured Villa sidelined for up to five months
Kings Cup: Real, Barca on course for last-eight showdown
Harish's Take: Dhoni disappoints as captain on Day 2
Kolkata set to play host to stars Pele, Cafu
Messi spurs 'invincible' Barca to World Club title