The 26-year-old has been ruled out of action for six weeks after it emerged that the Germany international picked up a knee injury during the 2-0 loss at Stamford Bridge earlier this month.
But despite Ozil apparently suffering the injury in the first half in west London, Wenger revealed that the World Cup winner did not inform him of the problem.
“He didn’t tell me anything during the game. I didn’t even know,” Wenger said.
“What happened during the game is that at half-time, just before we went out, the physio told me he had a little pain in his knee but it was not bad. He wanted to go on.
“I told him if you don’t feel well, tell me and I’ll take you off straight away. But he didn’t and after I left him on because we were in a position where we needed to score a goal and he can deliver a final ball.
“After the game he went [on international duty] with Germany, and they thought at the start it was nothing.
“They sent him for a scan and in this scan they discovered that he had a knee ligament injury that was quite serious.”
Wenger’s Arsenal host Hull City at Emirates Stadium on Saturday in the Premier League.
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