The London club need to beat the Greek champions either by two clear goals, or by any margin if they score at least three times, to progress from the group stages. If they fail to do so, they will drop into the Europa League.
Having lost the reverse fixture 3-2, Arsenal head into game with host of key players missing through injury, including forward Alexis Sanchez and midfielder Santi Cazorla.
Ozil, who has been involved in 14 goals in his last 13 Premier League appearances, is confident the Gunners can qualify for the knockout stages for a 16th consecutive year.
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"It will be very, very hard. Olympiakos can play good football and we saw that at the Emirates. They want to play on the counter-attack but we can't concede goals like we did before again," Ozil told the club's website (www.arsenal.com).
"The fans will be behind them and our goal has to be to beat them. I have played in Greece before. I know that there will be a very good atmosphere, the fans are crazy and they really support their team right through the full 90 minutes.
"We have to be focused on the game, we have to give a really good performance.
"It is possible to win there with two goals in our favour and that's what we want to do. We have to really give everything so that we can achieve this and get through to the next round."
(Reporting by Shravanth Vijayakumar in Bengaluru, editing by Ed Osmond)
