Casillas is thought to have grown tired of a rotation system at the Bernabeu, which sees himself rotated alongside Diego Lopez for La Liga, domestic cup and Champions League games.
The imminent arrival of Keylor Navas at the club has also thrown Casillas’ future into further doubt as he weighs up his next move.
Casillas remains a popular figure at his current club, a favourite of Real Madrid president Florentino Perez and a player that fans would prefer to see stay ahead of Lopez.
In a poll on the AS website at the time of writing, 47.70% of Real Madrid fans who voted suggested that Lopez should be the man to leave the club should Navas arrive as planned.
Casillas isn’t far behind on 42.86%, which suggests he’s still a very popular figure with the club’s supporters and someone they trust to perform in big games next season.
However, Casillas’ motives for leaving seem to be that he wants to be an outright number one again and that’s where Arsenal have a problem if they move for him.
It would be extremely harsh on Wojciech Szczesny if Arsene Wenger replaced him with Casillas before next season, as he worked hard to get the number one spot at the Gunners and deserves to start.
Wenger isn’t the sort of manager to treat his key players in such a way and therefore, it’s reasonable to suggest that Casillas would be Arsenal’s number two should he signed on the dotted line.
Monaco are also an option in Ligue One after they pulled out of a deal to sign Victor Valdes after the Spaniard got injured at the back end of Barcelona’s season.
Casillas would be a top class, consistent and highly experienced signing for Arsenal but his motives for moving may prevent a deal from happening.