The Frenchman was stretchered off the pitch during the Gunners' 2-2 draw with Manchester City last Saturday.
The former Newcastle United full-back confirmed on his Facebook page this week that he will discover today if he will need an operation after 'breaking' an ankle ligament.
In this morning's press conference, Wenger said: "We'll know tonight. If he doesn't need surgery, it'll be six weeks. If he does need surgery, it will be three months. At the moment we don't know."
Debuchy moved to the Emirates from Newcastle in the summer transfer window.