Iniesta and Marquez out of Barca opener
Spain midfielder Iniesta is recovering from a thigh injury and Mexico defender Marquez has been out with a calf problem, although the club said on its website that both were able to train as normal on Sunday.
Barca will also be without Lionel Messi because the Argentina forward is on international duty and Iceland's Eidur Gudjohnsen has not been included in the squad while he seeks to resolve his future with the club, they added.
Coach Pep Guardiola told a news conference the players were feeling the strain after their exertions in Monaco where they beat Shakhtar Donetsk 1-0 in the European Super Cup on Friday.
Playing extra time in the heat and humidity and the heavy state of the pitch in the Louis II stadium had sapped their energy, he said.
"We have conducted tests individually to see how they are," he said. "The level of fatigue is very high."
Guardiola added that the imminent arrival of Shakhtar defender Dmytro Chygrynskiy meant the squad was "virtually complete" and denied media reports that said Barca were poised to sign Brazilian forward Robinho from Manchester City.