Arsenal have enjoyed something of a revival under Unai Emery this season but they endured a nightmare first half against Crystal Palace as they found themselves on the back foot for much of the early stages.
The Gunners looked set to make it to half time with the scores level but it wasn't to be as the Eagles took the lead from the penalty spot thanks to a shambolic piece of defending.
Shkodran Mustafi gave away an inexplicable penalty when he hacked down Cheikhou Kouyaté and the Arsenal fans exploded with anger on social media.
The German has never really convinced in an Arsenal shirt and this was the latest mistake in the Premier League career of the German. It didn't go down too well on twitter...
Poor from Shkodran Mustafi to give away the spot-kick after a dreadfully mistimed challenge on Cheikhou Kouyaté lacking technique and any semblance of football intelligence - (@laythy29)
I’ll never forgive Arsene Wenger paying £35 million for Shkodran Mustafi. What a truly dreadful footballer - (@benegan97)
Mustafi is a walking accident. Time and time again he makes stupid errors. - (@AlexShawESPN)
Running out of words to describe Mustafi. Useless, useless bloke. - (@Frankie_Hobbs)
Arsenal had won eleven games on the bounce prior to the match at Selhurst Park but they clearly aren't the finished article based on the first 45 minutes. The defensive frailties that were all too evident under Arsene Wenger clearly still exist and with bigger tests upcoming, it is no wonder that the fans are worried.