Arsenal are reportedly in talks Barcelona at the Nou Camp this summer in the Gamper Trophy.

The ‘tournament’ is one that Barcelona play every season at the Nou Camp, inviting a side they would like to face.
This season it seems that the Catalans have been missing smashing Arsenal in the Champions League so have invited them to play this game which is likely to take place on 3 August according to Mundo Deportivo.
It could also take place on 4 August.
The only thing that seems likely to get in the way is if Barca win the Champions League and Arsenal win the Europa League.
The two sides would then be slated to play each other in the UEFA Super Cup so Barcelona would look for another side to play in the pre-season friendly.