"We all know that mental mindset is so important; that is one thing that only gets stronger with the setbacks."
Brentford's No 1 goalkeeper will be out of action for four to five months due to a knee injury.
Arsenal might sign whichever Championship goalkeeper makes a cock-up in the play-off final.
The Iceland international was signed four months ago to provide cover for Bernd Leno.
Arsenal have lined up two Brentford players to improve their squad for the upcoming season.