However, Pep Guardiola's men will be boosted by their aggregate Copa del Rey quarter-final win over their great rivals this week.
That cup victory was soured by the fact they could only draw 2-2 with Madrid in Wednesday's second leg after being second best for parts of the match.
Next they face a Villarreal team on a high following a return to winning ways in their last match against Sporting Gijon.
Cesc Fabregas expressed his disappointment at the loss of Andres Iniesta with a hamstring tear during Wednesday's match.
With Alexis Sanchez also suffering an injury and David Villa, Andreu Fontas and Ibrahim Afellay already absent, it leaves Guardiola short of options.
Fabregas, however, said: "There can be no excuses. We are FC Barcelona. We have to give our best and push on.
"There are players in the B team who are doing really well."
The midfielder added: "I feel bad for Andres but he knows we will be waiting for him. Together with Leo (Messi) he is the most incisive player in the game."
Jose Molina oversaw his first win since taking over at Villarreal when his side beat Sporting 3-0 on Monday but defender Gonzalo Rodriguez is under no illusions about the task his side face on Saturday.
"This year we've struggled a bit," the Argentinian told villarrealcf.es. "We were out of luck and we need a special night against Barca to boost our confidence.
"This is the perfect day to prove we are okay and that we can get out of the relegation spots."
Villarreal are still without key striker Giuseppe Rossi with a long-term injury.
Villarreal's cause may be hampered by the absence of goalkeeper Diego Lopez, who is doubtful with illness ahead of the match.