Arsenal boss Arsene Wenger has confirmed that defender Hector Bellerin will not play against Bayern Munich on Wednesday night.
The youngster will be replaced by 30-year-old Mathieu Debuchy who is fit enough to play the full 90 minutes according to the Frenchman.
The Gunners desperately need to avoid defeat if they are to keep their Champions League hopes alive.
"He [Mathieu Debuchy] will play and I'm confident, I trust Debuchy," Wenger told reporters.
"He is a very dedicated player and works hard in training. He played the full game fortunately last week against Sheffield Wednesday so physically he should be ready.
"I don't think it is easy to look for a draw. What we want is to play to win.
"When you are Arsenal and we have won everywhere in Europe, even here, we will try to win the game. Are Bayern a great team? Yes. But it is a good challenge for us to compete with them.
"We are in a period where we are doing well and that should convince the players we can do something right. We have a good togetherness and I believe we are a team that stick together when things don't go well.
"A defeat would put us in a very bad position.
"That is why we don't want to lose the game. We would still have a chance but it would diminish our chance to qualify, the best way is not to get into that position and get points tomorrow night.
"But I think it is a good opportunity for us to show that we are moving forward, that we are up to the test we face tomorrow. We have shown that in the first game. What you want is 100 per cent commitment from your players in an intelligent way."