Corica's future had been in some doubt after the Sky Blues crashed to eighth in the A-League Men this season, marking the first time since the 2015/16 campaign that the club didn't reach the finals.

But Corica's stunning success over his first three years in charge convinced the club's hierarchy that he was the man to lead the rebuild.

Hours after Corica's re-signing was revealed, Sydney announced the official departure of 12 players, including star striker Kosta Barbarouses.

Luciano Narsingh, Trent Buhagiar, Mustafa Amini, Harry Van der Saag, Callum Talbot, Anton Milnaric, Chris Zuvela, Calem Nieuwenhof and Liam McGing were also among the exits.

Brazilian forward Bobo had already announced his retirement, while former Socceroos defender Michael Zullo (calf) departed the club earlier this week after playing just one match in the past two seasons.

The futures of key players such as captain Alex Wilkinson, Milos Ninkovic and English forward Adam Le Fondre remain up in the air.

Barbarouses, who managed just six games in an injury-interrupted campaign, was the biggest name to depart.

Sydney didn't specify whether it was the choice of the club or the player to part ways.

"We look to the future and to freshening up the squad, which is going to be a major difference for us next season," Corica said.

"It's unfortunate for the players who are leaving, particularly those who have been on the long-term injury list, but we need to move on and rejuvenate the squad.

"We did offer contracts to a couple of players on the list, but they've made decisions that their futures lie elsewhere.

"That's football, you can't keep everyone in a salary capped environment, and there are a lot of younger boys (from our NPL squad) doing very well who are ready to step up next season."

Corica guided Sydney to three straight grand final appearances for a return of two championships and a premiership before this season's big form collapse.

His new deal, which will take him into a fifth and sixth season with Sydney, will see him become the longest-serving coach in Sky Blues history, surpassing Graham Arnold's record of four years.

"We understand it's not good enough to miss out on finals, so there's a lot of improvement we need to start making now for next season to get back into contention," Corica said.

"Recruitment will be key to our success as we freshen up the squad.

"We'll need a new striker, a new number 10 and I want to strengthen us defensively.

"We'll also be looking at changes to the playing style to give the boys a new approach to the season."

Corica's winning percentage of 51.33 per cent places him second behind Arnold (54.98 per cent) for coaches with 100 A-League games or more.

Australian Associated Press