Actually the keeper concerned is a pretty decent keeper by all accounts. (caughtoffside.com)
Cech did nothing extra ordinary that any other decent keeper would not do. (justarsenal.com)
Sad thing about it is Wenger doesn't a good keeper when he see's one, It's no coincidence that both Almunia and Fabianski became better keepers when they left Arsenal, I mean how does he let two decent keepers in Szcesny and Martinez leave and keeps an ageing Cech and average Ospina (justarsenal.com)