The 6ft 3in forward came off the bench during the 1-1 draw against Liverpool on Sunday and could have grabbed the headlines had he not missed an open goal in the closing moments.
"He is strong. You see his power when he first comes on and he can have an impact in games," Wenger said. "When he has come on he has had an impact every time.
"That is because he is intelligent and he is quick as well with a good technique so he has all the ingredients that the team needs.
"Nicklas is much different from the player that went to Birmingham. He has realised that it is a job, and a job in which you need to fight.
"Nicklas is able to say 'Yes I have to improve that, I was wrong there.' When you have this attitude, with the talent that he has got, you have a real great chance to be successful.
"He must continue to work as hard as he does. In this job that applies to a player no matter how good he is or how much talent he has - be ready everyday and when the chance comes to you, don't miss it."