Emiliano Martinez
Emiliano Martinez was a player that Arsene Wenger rated extremely highly. Still just 26 years of age, Martinez has his peak years ahead of him. Despite this, the moment Wenger left seemed to end any hope of Martinez breaking into the first team. Martinez has stated that he previously tried to leave Arsenal but Wenger promised him the future number one shirt in order to convince him to stay.
During an unsuccessful loan spell at Getafe last season, he made just five appearances. A total of 13 for Arsenal over a six-season period coupled with sporadic loans has left the keeper with just 57 professional career appearances. The signing of Leno has further blocked his route to the Arsenal first team and he has yet to even make a Premier League appearance.
A permanent move away from the Emirates looks like the only answer as this will allow the keeper to rebuild his career. Don't be surprised however if he is once again loaned out to either a Championship or Spanish club.