Barcelona head into Tuesday's Champions League clash with Celtic at the Camp Nou dogged by defensive problems.
• Barca thankful for win
• St Mirren 0-5 Celtic
Gerard Pique was again training alone in the gym on Sunday, while fellow first-choice defenders Carlos Puyol, Daniel Alves and Eric Abidal are continuing their own recovery programmes.
Elsewhere, Barca could be without Sergio Busquets following his red card in the side's previous group game at Benfica, with the club waiting on UEFA after appealing the decision.
If the appeal is not accepted then manager Tito Vilanova will be forced to play Alex Song in a deep midfield position, meaning Javier Mascherano and Adriano Correia will have to play in the centre of defence.
The makeshift nature of Barca's backline was again shown in the 5-4 win at Deportivo la Coruna on Saturday, where a Lionel Messi hat-trick was required to ensure his side remained eight points clear of Real Madrid in La Liga.
While Celtic will enter the game on a goal-scoring high after they showed their attacking potential with a 5-0 league win at St Mirren on Saturday.
It had been thought that Pique could return for the El Clasico clash with Real Madrid over two weeks ago, however, Vilanova said before the Depor game that the Spain international would not be rushed back from his ankle problem until he was ready.
"He's not 100% fit," Vilanova said. "If we didn't risk him against Real Madrid, then we'll be equally cautious against Deportivo, Celtic or Rayo Vallecano. He won't play until he's right."
Catalan paper El Mundo Deportivo reported on Monday morning that Pique was targeting Saturday's La Liga visit to Rayo for his return and that Puyol had an outside chance of making the game.