Neil Lennon will be without the Honduras international and Norwegian centre-back for the visit from the Liga giants in a crucial Champions League tie on Wednesday night
The Hoops' boss revealed that the Honduran full-back will be out of action for six weeks with a hamstring injury, while the Norway defender is also out of the Champions League clash with the Catalan giants after suffering a calf problem.
The pair join midfielder James Forrest and forward Lassad Nouioui on Celtic’s injury list with striker Gary Hooper also a doubt for the game at Parkhead - but Georgios Samaras could be fit to play.
"It's hugely disruptive as they are big players, have been for a while and were pivotal to how we wanted to play on Wednesday, but we still have a strong team to play," Lennon told reporters.
"It is important [Samaras] makes it anyway. He has been unlucky this season with injuries.
"Obviously he came back from Barca and played very well until he picked up the ankle injury. We are hoping he is going to make kick-off."
Lennon has insisted that his side must play with intensity and concentration if they are to beat the Group G leaders and get something out of the game.
"It will be a great occasion for the club," Lennon added. "It's our anniversary and something we are very proud of. It's a pivotal year for us, a year of celebration, and this would be the crowning glory.
"You have to play at your very best, with full concentration and great intensity. Sometimes even then that's not enough but we'll have a full house.
"We played very well in Barcelona, and at home and the crowd will inspire the players. Tomorrow night is important. If we can get something out of the game it would give us a strong foothold in the group."