Herd, 28, has been a free agent since being released by Gillingham in May after one season with the English League One club.

The Melbourne-born Perth-raised midfielder has been training with Wanderers and took part in Wednesday's behind-closed-doors friendly against Blacktown City.

FourFourTwo understands no guarantees have been made to Herd about a deal for the former Aston Villa man.

Herd hasn't played for Australia since October 2014

Wanderers have room in their squad, having let go 13 players this off-season, including midfielders Mitch Nichols, Dimas Delgado, Bruno Pinatares, Terry Antonis and Nicolas Martinez.

Western Sydney have made five signings so far this winter, with marquee Spanish striker Oriol Riera unveiled earlier this week.

Midfielder Roly Bonevacia, along with Josh Risdon, John Hall and Michael Thwaite are Wanderers other signings.

Any Herd move to Sydney would come barely 12 months after he walked out on Perth Glory due to family re-location issues.

Herd signed with Glory in April last year but mutually terminated his contract three months later without playing a competitive game in order to stay in England.