3. Mathieu Debuchy for Hector Bellerin
Centre-back Laurent Koscielny is in line for a well earned rest this week after looking jaded at the weekend. That will mean that Calum Chambers will likely have to shift over to partner Per Mertesacker in the middle. That will free Debuchy up to resume duties on the flank and help the Gunners learn to cope without Koscielny.