#2 Wojciech Szczesny
Szczesny joined Arsenal when he was a teenager back in 2006. Then, he rose to the first-team in 2009 before departing the club officially in 2017.
The Polish goalkeeper was dropped from the starting line-up in early 2015 when he was caught smoking in the changing room showers after the match. His lack of form also forced Wenger to promote David Ospina to the first choice keeper, leaving Szczesny on the bench for the rest of the season.
After Petr Cech was signed from Chelsea, the 1.95m tall goalkeeper dropped down the pecking order and was eventually loaned to Roma. By the end of the 2017 campaign, he had attracted interest from Italian giants Juventus as a potential successor to Gianluigi Buffon.
Now, Arsenal fans are unsatisfied with Cech for being unable to live up to the standards he had set while playing for Chelsea. As compared to other keepers, Ospina is considered short and that leaves him with a huge disadvantage during set-pieces.
Matt Macey, Arsenal's third-choice goalkeeper lacks experience in Premier League and there seem to be no reliable player between the posts.
It is one of Arsenal's biggest mistake to have let Szczesny leave the club.