The Premier League club Crystal Palace said on Wednesday that striker Christian Benteki had undergone minor knee surgery.
The 27-year-old has been out of competition since the start of September and withdrew from the Belgian squad during the last international stop.
"The club confirms that Cristian Benteki underwent minor laparoscopic surgery on his knee," Ballas said in a statement.
"The surgeon is happy with the result and we expect Bentici to return to practice very soon, we will keep you updated within a few weeks."
Beniteki has played four games for the Premier League this season but has yet to score.
Roy Hodgson's team are in 14th place and have not won the last three league games and will face a match against Everton after the international break.
