Barcelona must do without three key defenders for its home Champions League match against Celtic on Tuesday after Gerard Pique failed to recover from injury in time, coach Tito Vilanova said.
Pique, Carles Puyol and Dani Alves are all injured, forcing Vilanova to carry out a major reshuffle of the Barcelona defence.
"None of the three will play tomorrow," Vilanova told a news conference on Monday.
"For next weekend's game, we will have to see how they are doing," to know whether they will play against Rayo Vallecano in the league, he added.
Midfielder Sergio Busquets is suspended for being sent-off in the last group match, a 2-0 victory against Benfica in which Puyol dislocated his shoulder.
Alex Song has been linking with Javier Mascherano in midfield, but Vilanova may this time shift Song to fill the gap left by Busquets and hook Mascherano up instead with surviving defender Adriano Correja.
A possible alternative to solve the defensive problem would be to haul Cesc Fabregas into central midfield and keep Song back in a central defensive role.
Vilanova did not comment Monday on his strategy for taming the Scottish team, which managed a surprise win away to Spartak Moscow in their last game to leave them second in the group on four points.
"They were able to draw against Benefica and win away to Spartak," said Vilanova. "They are dangerous on the counter-attack and strong in the air, where we sometimes have difficulties. We have to watch out."
Barcelona are in pole position in their European group after back-to-back victories and can take a significant step towards qualifying for the last 16 if they come out on top against Celtic.
"Song and Mascherano are a good defensive pair," Vilanova said, fielding questions on Saturday's league match against Deportivo La Coruna in which Barcelona let four goals in to squeak to a 5-4 away victory.
"I don't think those goals the other day were their fault."
Vilanova also named Argentine superstar Lionel Messi in the squad for Tuesday's match, despite speculation in the Spanish media that Messi would be rested as his girlfriend, Antonella Roccuzzo, was due to give birth.