The 32-year-old shot stopper, who has a World Cup and two Copa Americas to his name, has reportedly been taken on as a client of renowned agent Jorge Mendes and his Gestifute agency.
Gestifute already represent a deep roster of top-class talent, including Ruben Dias, Joao Felix and manager Jose Mourinho.
READ MORE: The stats behind Worcester City's 2024/25 set piece goals
READ MORE: Every Word Chris Cornes said on Worcester City's play-off final win
READ MORE: Aston Villa FA Cup hero who spent time at Worcester City club dies aged 91
Martinez was previously represented by agency Universal Twenty Two, who boast names such as Alexander Isak and Luka Modric among their ranks.
It is understood that Villa will have to sell players this summer to comply with PSR constraints, with a £30million price tag thought to be enough to prise the Argentinian away.
Efforts are being made for a bigger money move, with the Saudi Pro League considered a potential option.