A decorated and composed central defender, Wilkinson, 31, joined City in February, inking a six-month contract until the end of the 2015/16 season.
A member of the Socceroos’ triumphant 2015 AFC Asian Cup Squad, Wilkinson has made 16 appearances for the national team, starting in each of Australia’s three group matches at the 2014 FIFA World Cup in Brazil.
Wilkinson returns to the A-League after first appearing as a foundation player for the Central Coast Mariners, making 172 appearances for the Gosford-based club and captaining the team for five seasons.
After leading the Mariners to the A-League Championship in 2013, Wilkinson moved to South Korean club Jeonbuk Motors, winning two consecutive K-League titles in 2014 and 2015 during a successful three-year stint in Korea.