Wenger left with a striker puzzle
Olivier Giroud's foot injury, which may rule the striker out for up to three months, obviously presents Arsene Wenger with a long-term problem. It might be one he can solve in the transfer market, and the pressure will be on him to address the Gunners' striking needs before the window closes on Monday night.
However, it also presents him with something of a short-term issue, because Arsenal face Besiktas in the Champions League on Wednesday without their best centre-forward. What Wenger does to replace him is going to be interesting.
He could give a runout to Yaya Sanogo, a player who, in terms of size and style, is the closest thing they have to Giroud. He'd be asked to do the same kind of job, to hold up the ball, bring others into play, and use his size and physique to unsettle the opposition defence.
It wouldn't be the first time the Arsenal manager has used him in such an important encounter. Last season he made his first start for the club in a crucial FA Cup fifth-round tie against Liverpool, and just three days later was again selected for the Champions League game with Bayern Munich at the Emirates.
So there's precedent, and it does suggest that Wenger is not afraid to use him when the pressure is on. There's only one real problem though: goals. The young Frenchman has yet to score a competitive goal for the Gunners. He might only have made 16 appearances in all, but it's still something of a gamble to hope it will be the night he breaks his duck. There's just too much at stake.
It seems most likely that Wenger will repeat the experiment of Saturday by deploying new boy Alexis Sanchez there. It's clearly something he had in mind when he signed him, saying, "He is a striker and he's a good finisher. I like the fact he can play left, right, up front, and that's why I went for him."
It didn't really work out at Goodison Park and it was Giroud's half-time introduction that helped Arsenal salvage the game, but in Europe, and at home, it seems a more natural fit.
With Mesut Ozil back in the team, and with a good 90 minutes under his belt, Wenger will be hoping that his two most expensive purchases can click and fire the team into the group stages of the competition.
The German is likely to find himself back in the middle as Arsenal have to navigate the test without Mikel Arteta and the suspended Aaron Ramsey. Having the former Real Madrid man pulling the strings with Santi Cazorla one side of Alexis and Alex Oxlade-Chamberlain on the other would give them a forward line of pace, power and creativity.
The issue for Wenger's team is that they looked far from comfortable with this kind of formation last weekend. Perhaps more time on the training ground will help, and having Ozil in a more central position will bring out the best in him, whereas he appeared a little lost at times on the left at Goodison Park.
It's a game that has enormous consequences for both teams. With the transfer window closing on Monday, qualification would make it somewhat easier for Arsenal to plug the gaps in their squad. They're on the lookout for defensive additions both at centre-half and in midfield -- and perhaps even a striker, with the Giroud situation -- but doing that business from the comfort of the Champions League group stages would attract players.
It's why they need to go with a team that has as much experience, quality and goals as possible. And even if the formation is something they still have to get used to, Alexis is a better bet to fire them through than Sanogo.