Following last weekend's 4-1 defeat at Stamford Bridge, the Irons remain very much in a battle for top-flight survival, just three points above the drop zone.
Wenger said: "I have a lot of sympathy for Gianfranco Zola because I like him very much as a person but my target is to win the game.
"For him, it will be exactly the same problem - they will try to win, we will try to win."
Wenger added: "The Premier League is very difficult, so nobody can be surprised by what happens to any team, because it is unpredictable and is so difficult this season for everybody.
"It can happen that when confidence drops, you lose points that are unexpected."
Arsenal - currently two points behind United and level with Chelsea, having played a match more - will welcome back captain Cesc Fabregas after the influential midfielder missed the wins over Porto and Hull because of a hamstring problem.
The return of the Spain international to his boyhood club adds to the spice for the European tie, with former Arsenal captain Thierry Henry now plying his trade at the Nou Camp.
Wenger, though, insists his squad must concentrate on getting the right result in Saturday's late kick-off.
"If you go to the bookmakers and try to place a few pounds, you will see that we are not favourites against Barcelona," he said.
"For me, we have a 50/50 game - if we turn up with our best performance we have a good chance to beat them.
"I believe it is much more important to focus on the West Ham game than the Barcelona draw.
"We have fought since August for the championship and it is important we keep our mind on what is vital to us - that is the championship, then we can go into the Champions League with the right belief.
"The West Ham game is the next game, and in football the next game makes your life."
Wenger, for one, will not be getting carried away in any pre-match hype ahead of the mouthwatering European tie.
He said: "The worry in the modern game is when you go to matches, you do not focus on football any more.
"When Chelsea played against Manchester City, people were more focused on the handshake of Wayne Bridge and John Terry. I was excited to watch a good football game.
"In our job, we have to make sure we focus on what is important and what we love, not the stories which the media dictates to people - it should be about what really matters to people, that means football."
Arsenal v West Ham. Click here to bet.