Holders Barcelona must beat Levski Sofia on Wednesday to make sure of avoiding a shock exit from the UEFA Champions League and some of their key players will not be there to help.
Coach Frank Rijkaard has only one fit striker in Eidur Gudjohnsen with Cameroon's Samuel Eto'o and Argentina's Javier Saviola and Lionel Messi all injured for the penultimate group match.
If Barca, who have not won a match in Group A since thrashing Levski 5-0 on the opening day, fail to collect three points in Sofia their fate will depend on the outcome of the other match between Werder Bremen and Chelsea.
A Werder victory and the Catalans will become the first defending champions to fail to get through the group stage since it was introduced in the 1992-93 season.
English champions Chelsea top the group with 10 points from four matches, Werder are second on seven, Barca have five and pointless Levski are bottom.
"We are playing for everything now and it would be unthinkable to see the next stage of the Champions League without Barcelona," said midfielder Andres Iniesta.
However, the performance of stand-in striker Gudjohnsen in Sunday's emphatic 4-1 win at Real Mallorca went a long way to allaying Barca fears with the Iceland international scoring a double.
OUTSIDE CHANCE
As well as three forwards, Barcelona will be missing midfielder Edmilson and right back Juliano Belletti.
On paper, Barca are hot favourites to beat the Champions League debutants but Levski have an outside chance of reaching third place in the group and a berth in the UEFA Cup if they win.
Levski warmed up in style for Wednesday's clash with a 3-0 demolition of city rivals Lokomotiv on Saturday that secured them top spot in the domestic league at the midseason break.
"I believe it will be our best display in the Champions League," said club owner Todor Batkov. "We can spoil the party of the European champions."
Levski have so far conceded 13 goals in the group but coach Stanimir Stoilov will have a rare chance to field a full-strength team.
First-choice goalkeeper Georgi Petkov has recovered from a finger injury and will replace teenager Nikolay Mihaylov.
Mihaylov, 18, had a nightmare debut in the Champions League against Werder last month and conceded a comic own goal in a 3-0 home defeat.
Lively striker Valeri Domovchiyski is also available after recovering from a groin injury and he showed his killer instinct by finding the net on Saturday.
Domovchiyski will be assisted up front by the versatile Hristo Yovov, who has finally rediscovered his scoring form by netting four goals in Levski's last three league matches.
Probable teams:
Levski: 1-Georgi Petkov; 20-Stanislav Angelov; 11-Elin Topuzakov, 4-Igor Tomasic, 25-Lucio Vagner; 6-Richard Eromoigbe, 7-Daniel Borimirov, 21-Dimitar Telkiyski, 27-Cedric Bardon; 10-Hristo Yovov, 17-Valeri Domovchiyski
Barcelona: 1-Victor Valdes; 11-Gianluca Zambrotta, 5-Carles Puyol, 4-Rafael Marquez, 16-Silvinho; 20-Deco, 3-Thiago Motta, 24-Andres Iniesta; 8-Ludovic Giuly, 10-Ronaldinho, 7-Eidur Gudjohnsen
Referee: Yuri Baskakov (Russia)