The striker silenced his England call-up critics by netting twice in the Europa League last 16 on Thursday evening.
But controversy surrounded Welbeck’s opener in the first half.
The former Manchester United man appeared to dive to win the spot-kick which levelled the tie at 1-1.
And eagle-eyed Arsenal fans have all noticed Nacho Monreal’s hilarious reaction.
As Welbeck runs up to take his penalty, the left-back has his hands on his head and is looking at the floor, clearly nervous his team-mate will not find the target.
A whole host of Arsenal fans reacted on social media after seeing the picture.
One fan commented, “Monreal was every Arsenal fan!”
While another wrote, “Monreal too obviously thought Welbeck might miss the penalty. I wasn’t alone in that thought.”
One other supporter also saw the funny side when he tweeted, “Monreal not trusting Welbeck anymore #ARSMIL”
And another Gooner said, “Monreal had a different image in his head!”
Welbeck has been criticised by fans and the media alike after last night’s clash.
But in typical fashion, Arsene Wenger refused to be drawn on the incident.
“I haven’t seen it again,” he said.
“Do you want to accuse English players of being divers?
“There’s two things: was it a penalty or not? I don’t know.
“The Italian players were unhappy with it.
“I can understand that, because I don’t really know what it was.”