Wenger has confirmed the France international is fit and ready to go against Champions League opponents PSG and believes Koscielny is now one of the best defenders around.
"I'd like to say yes," he replied when asked if Koscielny was one of the best defenders in the world.
"No one is indispensable, but he has taken on a new status with us. He has experience, self-confidence.
"He's always had talent, and that hasn't always been recognised in France because he left Lorient, not a big club.
"So he didn't have the reputation he deserved. But he's made his name in English football. I think he's one of the best in the world. I hope he proves that (against PSG)."