Kalac, who was born and raised in Sydney's west, has agreed to a one-year contract extension with the Sky Blues which will also keep himout of the hands of new crosscity rivals West Sydney who are also vieing for Popovic's signature on a coaching contract.

The former AC Milan goalkeeper would have been a candidate to join the new franchise's coaching staff but Kalac said he always hoped to remain with Sydney.

"Sydney FC is a great club with great facilities and I have really enjoyed coming to work every day since I started," he said on Friday.

"Staying at Sydney FC was the only option for me as far as I was concerned.

"I'm really grateful for the opportunity I was given when the position became available at the start of this year and I have enjoyed coaching the A-League keepers as well as the young goalkeepers coming through."

Kalac's first job will be to try and find a second keeper for the Sky Blues to work alongside No.1 Ivan Necevski, after the club sacked Liam Reddy at the end of the last campaign.