Arsenal manager Mikel Arteta says he wants his players to show courage when they face Olympiakos Piraeus in the Europa League at the Georgios Karaiskakis Stadium later on Thursday. Arsenal are expecting a hostile reception for the first leg of their round of 32 tie in Piraeus, where Olympiakos have lost just once -- against Bayern Munich -- this season. Arteta told reporters he wanted his side to keep their heads up even if things were not going their way. 'They can have the best intention but they need to go to a stadium like here and when they make a mistake or a bad decision, have the courage to try again and play again,' he added. 'And I want to see that in my players, whether they are 17 or 35. That’s what I expect from them. If they keep trying, they have my full support. If they hide after that, I don't like it.' Arsenal have confirmed playmaker Mesut Ozil has not been included in the squad due to personal reasons, while Lucas Torreira will miss out through illness. Arsenal have the chance to leapfrog Everton in the Premier League on Sunday when they meet at the Emirates Stadium but Arteta says that will not influence what team he puts out against the Greek side. 'We had a break of 15 days,' Arteta said. 'We played just one game so I’m going to send out a team that I think is the best to play. The rest of the game will take care of itself.'