Wenger explained: "I wanted to take him off because he had a little calf problem at half-time but he took advantage of that by scoring a goal. He scored a great goal again.
"Cesc is naturally very hard on himself. That struck me even when he was 16. He is very demanding of himself. He has his feet on the ground and I think he will deal well with that situation.
"We have played six games, four times at home, so we are conscious next week at West Ham will be another test. We won in a convincing way at Tottenham, we could have won at Blackburn so let us keep it going.
"There is still room for improvement and the target is to get better and better and hopefully peak in April and May."