Arsenal boss Unai Emery is holding extra friendlies for his senior players to improve their match fitness.
The Daily Mail says Arsenal defeated Arsenal 4-0 in midweek with Bernd Leno and Lucas Torreira featuring.
This is understood to be the third 'secret' fixture set up by Emery so far this season with Crawley Town having also faced the Gunners in London.
The Arsenal boss is keen to boost his players' fitness. The XI that started in their 2-0 loss to Manchester City did not take part.
Emery and Palace boss Roy Hodgson spoke afterwards and have agreed that, if both clubs find themselves in similar situations later this season, they will play again.