Hierro and two other Spaniards - ex-Atletico Madrid and Spain assistant coach Cesar Gonzalez Mendiondo and former Al Ittihad coach and Pep Guardiola confidant Raul Caneda - are being represented in Australia by Sydney-based agent Engin Durmus.

Speaking to The World Game, Durmus said Hierro would be a major coup for the league.

"Hierro has done everything in the game as a player but coaching is something that excites him now and he's expressed an interest in the A-League," Durmus said.

"He's aware of how many Spanish players have come here and done well, not to mention coaches like Gombau and Guillermo Amor.

"He sees this country as a new football frontier, as do Cesar Gonzalez Mendiondo and Raul Caneda, and he believes he would enjoy working with Australian players."

Hierro was appointed Sporting Director for the Spanish Football Federation only four months ago, but sources indicate he would prefer an A-League coaching role, following in the footsteps of Guillermo Amor and Josep Gombau.

Sydney FC are one potential high-profile destination for the Spanish trio, given the expected departure after the World Cup of coach Graham Arnold.