With a defensive injury crisis in full swing, Arsene Wenger is considering his options.
He has drafted in Isaac Hayden into the first team set up from the under-21 side, pictured above alongside Hector Bellerin.
He follows Semi Ajayi and Stefan O'Connor in making the step up, the latter of who came on against Galatasaray in the Champions League in midweek.
Arsenal have real problems defensively ahead of the match with Newcastle, with Laurent Koscielny ruled out with a calf injury.
Nacho Monreal is also injured, and Calum Chambers is suspended, with the only plus being Mathieu Debuchy's return to action in midweek.
The Frenchman could get the nod to play centrally with Mertesacker, and Bellerin at right-back against his former club. Alternatively Wenger could look to start one of the defenders against Alan Pardew's in-form side.
Here's a look at a number of other snaps from the morning's training session: