The Gunners managed to qualify for the knockout rounds following a 3-1 win over Partizan Belgrade on Wednesday.
Wenger said: “I was never really nervous. Worried yes, because you cannot say you don’t worry when it is 1-1.
“But I felt we had the resources to score and in the last 20 minutes they would drop physically. I was always confident that we would qualify but you never know.
“We didn’t find our pace in the game. We didn’t manage to find openings in their defence and they defended very well.
“We have a 50 per cent chance to travel to Spain and we have a 50 percent chance to travel to Germany. If you ask me what I prefer, I don’t know.
“Barcelona are super favourites in the competition. But we take what we get. We’ll see.”
He added: “Overall we are in a strong position in the league, we are qualified in the Champions League, we are in the Semi-Final of the League Cup and we start the FA Cup in January.
“There are plenty of exciting challenges in front of us but there is room for improvement and I am confident we will improve.”
