The Gunners are on the brink of missing out on a top-four spot in the Premier League for the first time in two decades, with Arsene Wenger's side requiring slip-ups from either Liverpool or Manchester City in the final week of the season.
The upcoming FA Cup final against Chelsea could provide consolation for Arsenal, but Koscielny admitted that he would choose a top-four finish ahead of winning silverware this season.
"Playing in the Champions League," he told reporters when asked to choose between the two. "It is a competition players want to play because you play against the best teams in Europe. For the players, it is always an important competition. It is important for Arsenal, a club who played for 20 years in this competition to be qualified for another year. It is very important for Arsenal to be with the best teams in Europe.
"We perform every weekend to be in the top four and to fight for the title over the season. To not be in the Champions League next season would be a very disappointing situation for us but we will fight until the end to have as much of a chance to be there next season. We have a small chance [of making the top four], but in football, you don't know, especially in England.
"All the teams can win against each other and we need to do our job first, to have the two wins and after that, we wait for the results of Liverpool and Man City. I think every game is important but now we are nearly at the end of the season, we have two games and we have to win them both so it starts with Sunderland.
"I think they just want to play and show they have the quality to play in the Premier League so I think it will be a hard game but we need to dictate our game, to have the possession, to play with more movement like we played this week and to have the best result for us."
Arsenal host Sunderland at the Emirates Stadium this evening before bringing their league season to a close at home to Everton on Sunday.