CELTIC have been given a glimmer of hope that the back door may be opening for them to get a result in Barcelona.

The Spanish giants have been hit by a quadruple blow as all four of their regular defenders are set to be missing when the Hoops travel to the Nou Camp a fortnight today.

Captain Carles Puyol is out for several weeks after severely dislocating an elbow playing against Benfica last week.

His partner in central defence, the very experienced Gerard Pique, is sidelined with an ankle injury.

Left-back Eric Abidal will not return to action until next month as he recovers from a liver transplant.

And right-back Daniel Alves has now joined them on the crocked list after damaging a hamstring and being forced off during Sunday's draw with Real Madrid.

With their defensive midfielder Sergio Busquets also out of contention for the visit of Celtic after picking up a red card during the 2-0 win in Lisbon, rookie boss Tito Vilanova will be forced to field as many as five deputies against Neil Lennon's side.

And, with several of his stars on international duty for the next 10 days, the Barca manager will have very little time to work with his makeshift back line ahead of the first in this double-header against the Hoops.

Vilanova was forced to omit central defender Marc Muniesa from the squad he registered for the Champions League group stage as he tore knee ligaments in a pre-season friendly and will be out for several months.

Martin Montoya came on for Alves in El Clasico, while midfielder Adriano was drafted in to central defence, but both were exposed several times by Cristiano Ronaldo and his Real Madrid team-mates.

Lennon acknowledges that facing any Barcelona side represents a massive challenge to the Hoops, who lie in second spot in Group G following their win in Moscow last week.

He will send his spies to watch Barca's game away to Deportivo La Coruna three days before his own team face Messi and Co. to see how their patched-up defence performs.

Lennon has already studied how Spartak managed to score twice in the Nou Camp before finally going down 3-2 on matchday one.

And, with the concentration of problems in one area of the Barca side, the Parkhead boss will hope to take advantage.