The Premier League rivals are both on the lookout for a new stopper, with Arsene Wenger unconvinced by current no.1 Wojciech Szczęsny, whilst Joe Hart's form has dipped in recent weeks, leading to Manuel Pellegrini to scour the market for a new recruit.
Casillas has become increasingly unsettled at the Bernabeu, with Carlo Ancelotti confining the legendary keeper to the bench so far this season, opting for Diego Lopez instead.
And with World Cup 2014 just around the corner, the 32-year-old is considering his future.
Reports suggest Casillas fears for his place in Vicente Del Bosque's squad if he is not getting regular first-team football, and is open to the idea of moving away from Spain.
According to French sports site Sport24, PSG are preparing to offer Casillas their no.1 jersey, with the ambitious outfit looking to become a major force in Europe.
The report claims that Casillas has already met with PSG's president Nasser Al-Khelaifi for preliminary discussions during a trip to Qatar.
And with both parties in contact over a possible switch, the ball is now firmly in PSG's court, who are aiming to beat Arsenal and Manchester City to the player's signature by meeting Casillas' buyout clause.