The Gunners boss urged his players to show the mental strength necessary to turn their season around, beginning with Saturday's trip to Anfield.
Victory would put Arsenal, who sit fourth, four points clear of Liverpool in the race for Champions League qualification, with a game in hand.
And Wenger knows negative thoughts and feelings about last month's 5-1 Champions League defeat in Germany will do his team no favours.
"When you have a bad result like that, of course it plays on your mind," he told the club's website.
"But I just think you have to focus on the way we want to play and on the desire to win, to fight and to take the opportunity you have to show your quality.
"After that, the recent history being negative, that doesn't help. But you have to be strong enough to deal with that.
"Things can change very quickly at the end of the season with many big teams playing against each other.
"It is very difficult to predict how many points will be needed [for a top-two finish] at the moment. We are in the mode now where we want to win our next game."
Arsenal have had a 12-day break since defeating Sutton United in the FA Cup, with Wenger warning his side they will need to guard against complacency.
He said: "For us, after a little break, it is important to switch on quickly. We have seen that is not easy - Liverpool showed that against Leicester.
"After a break, it is important that you are ready from the start again. You lose a little bit the rhythm of the competition and for us it is vital to start strongly at Liverpool."