Villa back in hospital due to kidney stones
The 31-year-old Spain international, who was first admitted on Monday and released a day later, was still in pain and would undergo more tests, Barca said in a statement on their website.
"The player is unavailable for the Granada game," they added.
Villa is working his way back to full fitness after suffering a broken leg at the Club World Cup in December 2011 and has not been an automatic starter under coach Tito Vilanova.
He has scored six goals in 16 league appearances this season and five in the King's Cup but has yet to open his account in the Champions League.