Graeme Souness accused Illan Meslier of costing Leeds United for all three of the first-half goals they conceded against Arsenal.
The 20-yer-old goalkeeper had an afternoon to forget after playing his part in a wretched first-half performance from Marcelo Bielsa's side.
Pierre-Emerick Aubameyang opened the scoring after deceiving the Frenchman at his near post having darted past Luke Ayling, cutting in from the left-wing.
Meslier then self-imploded after dallying in possession following a routine back pass, before bringing down Bukayo Saka after he dispossessed the 'keeper.
To make matters worse, Hector Bellerin fired in a third before the break, again beating Meslier at his near post.
Whilst Souness acknowledged the modern-day demands of a goalkeeper, he insisted Meslier was massively at fault for all three goals.
"This is a definite pen, Cooper with the back pass, it's the perfect back pass, right weight, it's not spun at him," Souness said at half time.
"He's got plenty of time to take a touch and launch it. I accept for goalkeepers today, it has never been more difficult. They're expected to pick passes and not just launch it.
"This boy, it's not the first one he has made a bad decision on. He's played a few straight out of play towards the right-back. It's a penalty all day long.
"When you look at this game, all three goals, the goalkeeper has had to play. Before the game, we spoke about the importance of having a good goalkeeper, this guy has cost them three goals, arguably.
"He'll learn it, but I've seen this from his before. Learn from your mistakes."
