Sydney coach Graham Arnold will need to find a replacement for regular substitute Ibini who, after two stints with the club, is set to sign to join MLS outfit Vancouver Whitecaps.

Sydney have agreed to release on-loan Ibini to his Belgian parent side Club Brugge, who are poised to receive a transfer fee pending a medical before the MLS window shuts at the end of Monday (US time).

The timing of the medical is unclear, given it's understood the hamstring injury that sidelined the 24-year-old for the grand final is more serious than it first appeared and will need up to 10 weeks' rest.

The Sky Blues' medical staff have been integral to Ibini's unlikely recovery from a badly broken leg and ligament damage, suffered during his first pre-season with Brugge in 2015.

It comes just two days after the Sky Blues sealed their premiership-championship double and coincides with the club also confirming the re-signing of star midfielder Milos Ninkovic, who will replace Filip Holosko as a marquee for 2017-18.

The considerable pay rise is fitting reward for the 32-year-old Serbian, whose stellar second season saw him named as the competition's best player. And for Arnold, it's a relief.

"I was confident, but I didn't know what Milos is thinking and what the discussions are behind closed doors with his wife and family," Arnold said.

"All I could do was encourage him and beg him to stay, and whenever I saw his wife I'd beg her to please stay as well.

"It's a great day for the club, he's a fantastic player and person with a great affect in and around the rest of the team."

Unbeknownst to Arnold, Ninkovic had privately decided to stay three or four months back when speculation about his future was still rife league wide.

Ninkovic said he and his wife made the final call together about a month ago.

"It's most important when you're happy off the pitch, you can play good," Ninkovic said.

"My family and I are happy here. And I am 32 years old, I am tired to move every two years to another country - it was difficult the first year I came here."

Ninkovic, who scored the title-winning penalty in Sunday's grand final against Melbourne Victory, will head home to Serbia this week, meaning he'll miss this month's friendly with Liverpool.

He'll return in time for the start of pre-season in July.

Arnold expected no more than three or four changes to his squad that defeated Melbourne Victory on penalties in Sunday's decider.