Arsenal Mustafi ruled out until 2017
Mustafi was taken off after only 25 minutes and was replaced by Hector Bellerin, who was only returning to first-team action.
“It’s a bad one,” Wenger said about Mustafi’s injury.
“The minimum [layoff] is 21 days. … That means he’ll have a nice Christmas.”
Mustafi was rested for the Gunners’ 4-1 win over Basel in the Champions League on Tuesday and Wenger confirmed he was carrying a minor knock ahead of that game, but was given the go-ahead by medics ahead of Saturday.
“He had nothing. I would not have played him today if he had [an injury] ,” Wenger said.
“Even he wanted to play in Basel, because he said, ‘No it’s nothing,’ and he was completely cleared. I checked three times, there was no problem before. I don’t know why it happened. But it looks a good hamstring strain.”