The versatile Milligan finished his second and final season at Baniyas SC in the United Arab Emirates on Sunday.
He played 22 of the side's 26 league games, scoring two goals.
It was an unhappy season for Baniyas though, who were relegated after winning just three matches and finishing bottom of the UAE League.
Goalscoring wasn't a problem for Baniyas as they found the net more often than a number of sides that finished higher up the table.
However, the 70 goals they conceded was easily the most in the 14-team competition.
Milligan’s next move is yet to be confirmed but there will no shortage of clubs chasing his signature.
The veteran international continues to be a mainstay in the Caltex Socceroos, playing 90 minutes in the two most recent World Cup qualifiers against Iraq and UAE.
He also played in nine of Australia's 10 internationals in 2016 and has a total of 55 caps for his country.
Milligan is sure to again play a huge role in the World Cup qualifier against Saudi Arabia in Adelaide on June 8 and the Confederations Cup in Russia later next month.