I’ve sort of always sympathised with Arsenal here. It was a tricky call to make, and one that definitely looks bad in hindsight
I’ve always thought Leno was a bit shit, and was very much for keeping Martinez instead, but that was never an option because nobody was in for Leno. Martinez never ever looked like he was going to make it either, had a series of unremarkable loan spells and then suddenly hit a massive run of form. There’s a horrible amount of risk involved in putting your eggs in that basket if it was just a hot-streak. It would be the best time to sell a player like that, Arsenal needed the money, and it was in a position where it’s filled by a “good” player already.
What we should’ve done is have sold Maitland Niles to Wolves when they put in that £20m bid for him, kept Martinez as #1 and sold Leno this season. But that’s with the benefit of hindsight too.