Arsenal are preparing for Europa League semi-final clash with Valencia and the Gunners are getting prepared for the upcoming match at Colney.
Eagle-eyed photographer spotted something that will definitely interest Arsenal fans and rivals.
Unai Emery accidentally revealed a little more than he would have linked on his tactics clip board.
Pictures taken by Arsenal show the Spaniard's ideas ahead of the first leg, and it appears he plans to play with three at the back.
According to the image, below, the Gunners are set to play 3-4-1-2 at the Emirates, with Mesut Ozil playing behind Pierre-Emerick Aubameyang and Alexandre Lacazette in attack.
The Gunners come into the game on the back of three straight defeats.