Arsene Wenger has revealed the midfielder needed surgery on his knee after his recovery from a ligament problem had stalled, while Yaya Sanogo could return in November.
The France international has been plagued by injuries throughout his career and, after requiring another operation, now faces a six more months on the treatment table.
“He had a little key hole surgery again, on the the knee because his knee blew up every time he did something so it is now six months after the cruciate,” Wenger told reporters.
“He could not even jog yet so with new surgery it is a set back for him so competitive football cannot be played before March.”
Though the 27-year-old has completed 90 minutes just twice since 2011, Wenger appears intent on sticking by the midfielder and played down suggestions he would be offloaded, adding: "He has one and a half years to go on his contract."
The Gunners have a number of other injury concerns, with Lukas Podolski and Alex Oxlade-Chamberlain also out of action, while Yaya Sanogo "could be the earliest one [to return] which could be mid-November."