Melbourne City will start the search for Alex Wilkinson's replacement, but will take their time finding the best player to fill the Socceroo centre-back's shoes.
Wilkinson signed a two-year deal with Sydney FC on Tuesday, bringing an end to his three-month stint with City.
The 31-year-old joined City in February after leaving South Korea's K-League title-winning outfit Jeonbuk Motors late last year, but had left his future open following the end of this A-League season.
City were keen to retain the World Cup and Asian Cup Socceroo, though they faced stiff competition from Sydney and Wilkinson's former side Central Coast.
He eventually chose the Sky Blues, where he will slot into the central defensive spot vacated by new Mariners signing Jacques Faty.
City finished the regular season with the worst defensive record of any team in the top six, with 44 goals conceded.
And though coach John van `t Schip was disappointed to lose an experienced player who provided much-needed stability at the back, he wished Wilkinson well and looked to the future.
"We wanted to keep him, but we understand also the choice of Alex to go to Sydney," Van `t Schip told AAP.
"We knew from the start that he would come for a few months and then make another decision after, and he was doubting to stay.
"He's a great guy, we wish him all the best. And now we have to find a replacement.
"Of course we have ideas, but we have time. We don't have to rush."