However, the best-case scenario for Arsene Wenger come the beginning of next season would be to see the Spanish international jostling with Wojciech Szczesny for the No. 1 jersey. Polish newspaper Przeglad Sportowy, via Sky Sports, quotes Szczesny, who is up for the challenge:
If they give me a contract to the end of my career, I'd sign it without any hesitation. I feel attached to the club and the coach who has given me a chance. There are not many who would do that but I must have been good. I see the future here.
I'll play at Arsenal as long as am wanted here. I am not afraid to fight for number one with anyone: Fabianski or Casillas. I hope I won't make the boss think, "Wojciech's not number one." It's all in my hands. I am in the best form of my life.
Szczesny's attitude toward such high-profile competition is endearing, and Wenger should see it as a major positive that his stopper looks so kindly upon the prospect.
Having recently beaten Tottenham in another North London derby, the Polish international showed just how much he adores his club, per Arsenal's official Twitter account:
Another factor in this arrangement is that Arsenal look likely to free up numerous goalkeeping spaces in their roster this summer. Lukasz Fabianski is out of contract in July, and Sky Sports confirmed in February that Szczesny's compatriot would not be signing a new deal in North London.
What's more, Emiliano Viviano's season-long loan from Palermo is set to come to its end in three months' time, and the fact that the Italian is yet to make a senior Arsenal appearance suggests that his stay won't be extended.
Juggling two top-class goalkeepers at a club of Arsenal's stature is a formula few managers opt to put into effect, but the balance may be right for a successful experiment in this case.
Casillas has fallen behind Diego Lopez in Real's pecking order for going on a year now, restricted to prominence in just European and Cup competition.
OptaFranz show precisely what kind of pedigree Arsenal would be getting their hands on with Casillas:
It's far from guaranteed that the Spaniard would bear any more fruit in North London, but with one-half of the potential tandem already on board with the idea, it seems only a question of whether Casillas would be willing to take the risk.
Szczesny is an ever-improving force in the English top flight, but the Pole isn't yet among the European elite. Casillas' credentials as a world-class talent are well-known.
Should Wenger see it as the right fit and feel that he's able to satisfy both players' expectations, the Frenchman could have a very promising partnership on his hands next term.