The Holland striker was due to make his comeback, starting from the bench, against Tottenham in the north London derby at White Hart Lane.
And Wenger has pledged to go all out for the victory which would see his side leapfrog Manchester United in the Premier League table and keep their title ambitions alive.
The Frenchman said: "When you know how much Robin loves football it's been a very tough time, but he has certainly come through with a different appetite and stronger as well for the future of his career. I am very happy he is back.
"What is most satisfying for me is that in training he looks like he has never been out."
Sol Campbell was set to start in central defence against his former club and Wenger believes the break Arsenal have enjoyed since losing the Champions League semi-final to Barcelona a week ago will have refreshed his side.
"The little break was welcome because it was a big disappointment to go out of the Champions League," said Wenger. "But it gave us time to reflect on our campaign.
"Overall I am very proud of our commitment - it will help my team to improve from that. I am convinced that defeat will allow us to go a step even higher up now."
With Tottenham smarting from their FA Cup semi-final defeat against Portsmouth but still chasing fourth place in the Premier League, the derby is bound to be a tense and feisty affair.
Wenger said: "We know to win the championship anything other than a victory is not good enough so we go with that desire, with that firm intention to win the game. We will not go for a draw."
On who might be eventual champions, he said: "Rule nobody out. Chelsea are in a strong mathematical position but that doesn't mean that it will happen as predicted because this league is special this year and unpredictability is what we have learned about this whole season."