Cisak will challenge Andrew Redmayne for the number one spot this season after the departure of Danny Vukovic, 

The 28-year-old joins the Sky Blues after two years with Leyton Orient in League One. 

Cisak has spent all of his professional playing career in England after moving to Leicester City's youth team in 2005 as a 16-year-old. 

While he did not feature for the Foxes, he has made appearances for the likes of Portsmouth, Burnley, Oldham Athletic and Accrington Stanley among others. 

“It feels great to be heading home and to be helping the Hyundai A-League Champions defend their titles this year,” Cisak said.

“After 12 years playing in England, the lure of the A-League and AFC Champions League football was too much.

“The A-League was only just beginning when I left to join Leicester City in 2005, and to be coming back to play for Australia’s number one side is a dream come true.

“I’ve heard a lot about the league from friends in recent years, not least how impressive the standard is and I can’t wait to get started on the challenge.”

Sydney FC coach Graham Arnold added: “We now have two excellent number one goalkeepers fighting for the number one spot which can only be good for us,” he said.

“Alex has proven how talented he is by surviving for 12 years in one of the world’s toughest leagues.  It wasn’t long ago he was called into the Socceroos squad and I expect him to be challenging for that again when he produces the form we know he is capable of.

“With Andrew Redmayne’s performance against Arsenal on the back of reaching a Grand Final last year, we now have two of the best goalkeepers in the country at our disposal.

“I look forward to both of them developing well under John Crawley.”