Arsenal striker Olivier Giroud has insisted that the Gunners will have to give their as they face Olympiacos in the Champions League this evening.

The North Londoners take on the Greek champions in the Karaiskakis Stadium, needing to beat them by two clear goals at least to reach the knockout rounds of the competition.

Giroud has claimed that while Arsenal are missing a number of players through injury, they still have enough quality to get the result they need in Piraeus.

"We'll have to be at 100% because 95% won't be sufficient," he told L'Equipe. "It's a group that was in our range and we put ourselves in difficulty by losing our first two matches, now we have the chance to show our mental strength.

"We must have 40% of our team missing, but we have a more well-equipped squad than in previous years.

"The guys who have replaced them did the job at the weekend, like Joel Campbell. We know that we have the quality to impose ourselves there."

Olympiacos beat Arsenal 3-2 when the sides met in the reverse fixture at the Emirates Stadium.