Gibbs suffered a metatarsal injury in November last year that ruled him out for the rest of the season, and Wenger believes he is likely to spend another significant spell on the sidelines.
"We lost Kieran Gibbs last night," Wenger told Arsenal TV Online on Thursday. "That is the bad news. It is a medial knee ligament strain. It needs to be checked on the scan tomorrow but it will be a few weeks."
"We have nobody else back from Manchester City. Van Persie and Vermaelen are still out, Ramsey and Almunia are not ready, so it should be a similar squad to the one that played at Man City, but Van Persie and Ramsey are very close to coming back to full training now," he said. "They should be back in the group at the end of next week.
"Of course we should not set the same [recovery] time to Ramsey as Van Persie. Aaron will need a longer period to be completely match-fit for the first team, but Van Persie is not far away now.
"Manuel Almunia is maybe one to two weeks away. With Vermaelen, it is difficult to set a fixed time because he Achilles improves slowly."