The Gunners headed into the clash suffering from a number of injuries and they were struck again early on, Francis Coquelin being forced off in the first-half with a knee complaint.
While replacement Mikel Arteta is a competent player, he doesn’t provide the same sort of defensive protection and Arsenal soon started to lose their grip on the match soon after taking the lead.
Olivier Giroud’s flick was immediately cancelled out by James Morrison, and five minutes later another ball into the area caused havoc and found its way past Petr Cech via Arteta’s arm.
"If Martin Keown was in that defensive position that goal would not have been conceded. Nobody attacked the ball, no-one headed it. Weak, fragile defending, from Arsenal,” Mills explained.
The former defender added following West Brom’s second: "There was no danger - I don't know why Mikel Arteta was that close to Petr Cech. There was no need for him to be there. It's awful."
To make matters worse, Arteta also suffered an injury and had to be replaced by fellow holding midfielder Mathieu Flamini, leaving the Gunners very short on options through the middle.
The number of injuries will only raise further questions regarding Arsenal’s training methods, but also the decision not to sign any outfield players over summer is looking more questionable with each passing week.
Arsenal’s miserable afternoon was compounded with a late penalty miss from Santi Cazorla, the Spain international slipped at the crucial moment and saw his effort go way off target.