Busquets was carried off during the first half of Barca's King's Cup semi-final clash with Villarreal after an accidental collision as he attempted to block a pass by Tomas Pina.
“The player has an injury to his right ankle,” the Catalan club said in a statement.
"More tests will be carried out tomorrow to determine the extent of the injury."
(Reporting by Tim Hanlon; editing by Toby Davis)
