The moment Chile went out of the World Cup was a game changer and Sanchez was dead set on leaving Arsenal quickly. At 29, his last shot at glory for his country was gone and he wanted to join a club with a chance of winning silverware. Sanchez also switched off in training and was petulant on the training ground - last year he was dropped at Liverpool for having a bust-up after storming off. That got worse. His levels dropped, he was the first to leave and displayed more arrogance than usual.
His goals and assists - to some that is all that matters - masked abject performances on the pitch when he hid his lack of contribution by throwing tantrums.
It was designed to show he cared but team mates felt the opposite was true. Sanchez seemed to enjoy breaking rules by going into the gym with his shirt off - and then take pictures of himself to revel in it. He never got involved in team meals, bonding exercises and kept himself to himself.
Wenger seemed nervous about substituting him. In one game, he took him off at the Emirates with ten minutes left. Sanchez stormed back to the dressing room, showered, changed and cleared off before his team mates finished the game.