Arsene Wenger says Barcelona's improbable exit from the Champions League serves as "a good warning" that Arsenal can't be complacent when they face CSKA Moscow in the second leg of their Europa League quarterfinal on Thursday.
Arsenal hold a 4-1 lead from the first leg and will try to avoid a repeat of Barcelona's failure to protect a similar advantage against Roma, as the Italian side advanced after a 3-0 home win on Tuesday.
"Last night is maybe a good warning for us," Wenger told a news conference in Moscow. "But let us not go overboard as well. Yes, we have a big job to do but we are in a strong position and it is how we approach the game that will be vital tomorrow.
"We are in a position where I don't think we are under threat of complacency, it is an important target for us to go as far as possible."
Centre-back Shkodran Mustafi said he watched Roma's comeback on TV and that it served as an important reminder that the job is only halfway done.
"I think it came as perfect timing for us, to see that it is football, you are never safe especially when you win at home and have the away game," Mustafi said. "You have to be very careful how you show up and I think the game we saw yesterday was perfect timing for us to show us that we have to be really focused and really concentrated to finish off the job we did in the first leg."
Arsenal will be without Granit Xhaka because of an illness, while Henrikh Mkhitaryan is sidelined with an injury. But Wenger pledged to field the strongest line-up possible, acknowledging again that the Europa League is now his main focus with a Premier League top-four place out of reach.
"Yes we have an advantage but the best way to build on the advantage is to try to win the game, we play with our best possible team, have a positive attitude and try and win the game," Wenger said.
"The Europa League is important for us, everyone knows that. We are at a stage where we focus on it because in the Premier League we have a very, very, very slim chance to move further up so the Europa League is one of the big targets now."
The Frenchman also insisted he has no worries about the current political tensions between Britain and Russia. Arsenal are the first major English sports team to play in Russia since the poisoning of a former spy in Britain.
"On that front there will be no problem. We've been well welcomed here and we have no problems to come here, and I don't think that will affect the game," said Wenger, adding that this summer's World Cup in Russia could even have a positive effect on the current tensions.
"Sport can always play a positive role in life, and between countries as well. That's why football is always a good opportunity to facilitate relations. I'm convinced that tomorrow night will be absolutely normal and that the World Cup will be perfectly well organised. But maybe sport will have a more active role during this time than ever."