Xavi struggling with a hamstring strain
The La Liga leaders did not say how long their influential playmaker would be out of action, but pointed out in their statement that he had suffered a torn muscle in the same area at the beginning of February.
Xavi was rested from Spain's World Cup qualifying draw against Finland on Friday but returned to help the side defeat France 1-0 in Paris on Tuesday to go back to the top of their group.
Barca have been using the 33-year-old sparingly of late and he has only featured in one of their four games in all competitions in March - the Champions League last-16 second leg against AC Milan, which they won 4-0.
The Catalans have a growing list of injury concerns before Tuesday's first-leg trip to Paris Saint-Germain after left-back Jordi Alba and Pedro returned from international duty with hamstring and calf problems respectively.
The trio join captain Carles Puyol and defender Adriano Correia in the treatment room. Goalkeeper Victor Valdes is suspended for Saturday.