Arsenal's French international defender Laurent Koscielny has plenty of sympathy with the Norwich City backline tasked with keeping tabs on red-hot Alexis Sanchez at Carrow Road this weekend.

The Chilean attacker notched a brace in the Gunners' vital 3-0 Champions League win over Dynamo Zagreb to take his personal tally for club and country this season to 12 goals in 23 appearances.

Alex Neil's squad must find a way to subdue Sanchez in Sunday's televised Premier League tussle, but team mate Koscielny admits the 26-year-old looks unplayable.

'Alexis is interesting when he plays with the ball. With the runs (he makes) he's very important because he's so quick. For the defence, it's very hard to defend against him,' he said. 'I think all the team did a great job. We defended well together, as a unit and like we did before this season. It's important to keep this for the next game, against Norwich.

'We kept a clean sheet so that's very important because the last result (at West Brom) was not good. Now we have a chance to qualify for the next round of the Champions League. After 10 or 15 minutes, we played with more confidence. After we scored, it was easier to play. In the second half, we scored another goal.

'For us it was most important to win, keep a clean sheet and have the cards in our hands for the last game at Olympiacos.'

Gunners chief Arsene Wenger admitted he was tempted to withdraw Sanchez in the second half against Zagreb to protect him for the league trip to Carrow Road.

'I would have loved to do it but I (had) two different options,' he said. 'Once it is 3-0 you are not in a position where you need him to work back and when you put him central up front you can spare a bit of energy – it is not like you have to go up and down the field. I tried to compromise a little bit and give a break to (Olivier) Giroud and not take a risk with (Hector) Bellerin.

'I don't know how important, percentage-wise, he is. He is just a very important player because at the moment we have only two real strikers. We have Giroud and Alexis so at the moment all these strikers are needed. Giroud had a little problem with his ankle over the weekend but I decided to give him a breather. Hector I took off because he had a groin problem just before meaning I could not take Alexis off, but we now have five days or so to recover for Norwich.'

Wenger is demanding total focus on the Canaries game following the recent 2-1 league defeat to West Brom after setting up a Champions League duel against Olympiakos for a place in the knock-out phase.

'It was important to respond to what happened at West Brom as confidence can drop quickly. Hopefully we can do that again at Norwich,' said the Frenchman.

'We played at a good pace and produced a game of quality that we wanted. I believe the speed of our movement and passing gave Zagreb a problem. From then on, once we had scored the first goal you could see the chances were coming. It was important that we did not concede the first goal as we looked dangerous (going) forward. Overall we had a game of quality that we controlled well.

'What we wanted was to come out of the game with a chance to qualify and we needed to do the job and Bayern Munich needed to do the job and they did that well.'