Speculation is mounting about the future of former Western Sydney Wanderers star who has not featured in Greentown’s preseason preparations in Barcelona.

The Green Giants have filled their foreign quota with a winger and two forwards and website transfermarkt lists the Australian as a free agent.

Spiranovic, who has 35 caps for the national team, is currently in Melbourne receiving treatment for a hamstring injury, according to The World Game.

The 29-year-old left Wanderers for the Chinese second tier side in July 2015, and is now in a race against time to secure the confidence of new Socceroos coach Bert van Marwijk ahead of Russia 2018.