The Gunners were held to a goalless draw in Turkey on Tuesday night in the first leg of their playoff tie.
Despite failing to seize the initiative against the Turks, Szczesny is confident that Arsenal will still go through to the group stage of the competition.
"We always want to play better and the only thing we can focus on is getting a result in the second leg," he told the club's official website. "It doesn't have to be a pretty one but we want to get through and secure Champions League football.
"It was a good test for us and we came out with a clean sheet which is a positive. We'll be confident going into the second leg."
Arsenal are back in action on Saturday when they make the trip to Everton in the Premier League.