The striker missed three one-on-one chances in a thrilling 2-2 draw at the Emirates Stadium, the last of which came after Hector Bellerin fired home the Gunners' equaliser in the 92nd minute.
The Spain global looked to have made a costly error when he clipped the foot of Chelsea's Eden Hazard in the penalty area which allowed the Belgian to make it 1-1 from the penalty spot after Jack Wilshere had put Arsenal ahead on 63 minutes. Referee Mike Dean was Wenger's target at West Brom for awarding the hosts a soft penalty for a handball by Arsenal defender Calum Chambers. "What I find awful is we just saw a great game and we talk only about this and for me it would be nice if we think about football for a change", he said.More news: Tesla Model 3 delay raises cashflow risks, but analysts upbeat
Meanwhile, Arsenal's inability to capitalise on Wilshere's opener saw them end the game five points adrift of the top four and Champions League places.
Speaking after the game Wenger said: "It was a great football game. I'm so proud to play for a big club like Arsenal".
Morata, meanwhile, had hit just two in his previous six games, but the Spaniard faced Arsenal having scored just once against a top-six rival since his £60m summer arrival from Real Madrid.More news: 2-hour computer outage at United States customs causes delays nationwide
Who takes it - Forest or Arsenal? Morata had a poor night squandering other opportunities as well.
"(I will contest the charge) 100 percent.
It seems inevitable that Sanchez will go, with Manchester City his preferred destination.More news: Supermoon New Year's 2018 Tonight
How long Sanchez maintains his form and contribution remains to be seen, but it is better for him and Arsenal if he keeps going as he is, rather than taking his foot off the pedal.