Arsenal goalkeeper Matt Turner received a scathing review from legend Martin Keown.
The no.2 shot stopper was in goal for the Gunners in their Europa League round of 16 first leg against Sporting CP on Thursday.
The Premier League leaders could only manage a 2-2 draw in the away leg, leaving them needing a win at home to progress.
"Really, he killed everybody with the first goal because he starts to come and then he goes back. (Jakub) Kiwior has got to do more than that too but if I'm playing regularly with this goalkeeper, I'm thinking I'm going to have to try and head things, because I can't necessarily trust him," Keown said on BT Sport.
"He had a first scary moments in the first half. He's got to come and be dominant and win the ball from the corner, but he didn't do it. The goalkeeper has to learn from it. You make up your mind to come for the ball and you go and reach it at the highest point.
"If you look, the goalkeeper comes and then he backs off. He kills the central defenders. I tell you what I'd do when I'm playing for the next one, I'm coming, I'm heading that. I'll take my own goalkeeper out because I can't rely on him.
"For sure, (Aaron) Ramsdale would have come and dealt with it. But then it's a goalkeeper who's not played much football, so let's give him a little bit of a break, but then he has to learn doesn't he? He has to learn quickly from his mistakes."