There are many voices, even among Aston Villa supporters, who have somehow come to the conclusion that Emiliano Martínez is a poor keeper. While pointing to some of his past heroics, including during the Argentine path to a World Cup victory. The critics believe that he is merely a shell of his former self.
By making such claims, one has to ignore the nature of the goalkeeping position. It is the area on the pitch where everyone knows when a mistake has been made. Even routine saves and easy situations are overlooked and can be taken for granted.
During the speed of a match, a lot happens. Activity in front of net, in particular, can become very busy and intense. Having someone experienced in these areas and able to more often than not prevent a goal from happening is extremely difficult to find.
When a club does have someone of a world-class caliber, it becomes all the more important to make sure that they stay for as long as possible.
Someone is always up-and-coming. Certainly, Lucas Chevalier appears to be an excellent young talent and should have a chance to showcase his skills at a high level with a top club soon enough. In the event of an actual (to this point, still unverified and unsourced) departure of Martínez, the Frenchman would be a good replacement option that Villa could build around for the upcoming years to come.
That is an entirely different conversation.
Martínez is a proven keeper that Aston Villa should strive to keep
To act like Martínez still isn't the best overall keeper in the world and still a reliable option is silly. Of course, he's made mistakes. Every keeper will, and the time comes when they will enter a particularly rough stretch.
Being too willing to move on from the Villa and the world's No. 1 shows a lack of appreciation of what is required of the position and how well Martínez has performed for Villa through his time in B6.