Maybe he thought we weren’t playing to his strengths?
Exactly what i thought at the time Cass when saw him subbed on Iornarmy YT Vid .. was arsey cos played out of position / different position to accommodate Wreh and less chance of scoring ..he obviously thrives on goals and maybe has his eye on the Golden boot (or flip flop such is the pitch)now Whall gonna be missing … good for the CV and his next move.
Also it was one of his less effective non prominent games so probably frustrated as mentioned after all he is the star of the show in most outings.