Melbourne City are fresh off completing a premiership-championship double but coach Patrick Kisnorbo says he's already turning his focus to building sustained success.

Bar conceding the opening goal, City dominated most of Sunday's grand final at AAMI Park - where they beat Sydney FC 3-1 without Jamie Maclaren, Curtis Good and Connor Metcalfe - in an ominous statement ahead of next season.

Kisnorbo has led City to their first premiership and first championship in his first year at the helm, but played down his achievement.

"Honestly after tonight, it's a new start for the next season," Kisnorbo told reporters.

"So I'll look at some things and say some good things but we have to start already preparing for next year.

"Because it's no point just trying to do things once - look at Sydney, they've had continued success.

"We want to do that."

The champions have already set themselves up for dominance, locking in Maclaren and Andrew Nabbout until the end of 2023-24, while Socceroos forward Mathew Leckie has joined for the next three seasons.

But perhaps even more encouraging are the young guns who've shown they belong - namely Metcalfe, Joe Marston Medal winner Nathaniel Atkinson, Stefan Colakovski and Marco Tilio.

"It's not just any young player that's able to walk into this club and into the team. They need to be patient, they need to learn and listen," Kisnorbo said.

"But those four - and there's others - they haven't been here just for two minutes.

"They've had to learn the reality of what professional football is, it's not just 'I've come to a club and I'll play'.

"They've done it hard and it's credit to them that they've really worked hard to put themselves in a position to reap the rewards."

One thing Kisnorbo will continue to do is lean on former head coach and mentor Erick Mombaerts, who left a few "texts and missed FaceTime calls" for him post-grand final.

"We speak four times a week. He's like a best friend of mine, not just a mentor," Kisnorbo said.

"We speak regularly, and it's great to have the relationship with the guy. He just wants us to do well and also he critiques a lot of stuff - he tells me if it's not good and, how (I can) improve.

"So as much as he helps and supports, he's also a critic of mine, but in the way to learn and that's where I'm grateful to have someone like that in my life."