Marco Materazzi is a free agent after the defender terminated his contract with Italian giants Inter.
The decision was taken by mutual consent after the player reportedly held talks with owner Massimo Moratti.
The veteran, who will be 38 in August, had 12 months remaining on his Stadio Giuseppe Meazza deal.
The stopper, who won the 2006 World Cup as an Inter player, joined the Italian giants in the summer of 2001 from Perugia.
Matrix, who is now available on a free transfer, could continue his playing career in America or England.
He's expected to return to Inter at some stage in the future once he decides to hang up his boots.