The Sky Blues' dominance of the A-League finally ended during the 2020-2021 campaign as Melbourne City won both the league and the grand final.

Sydney FC went down 3-1 in the decider in June and had Luke Brattan sent off in the first half.

Retre concedes that grand final result has been hard to get over, but also provided fresh motivation for this team for the new season.

"Look, it's probably not that great to dwell on the past and you want to look forward," the right back told FTBL.

"But even for the players it's left a bit of a bitter taste... just the way we lost with the red card and not knowing exactly what would have happened if there were 11 players on the pitch.

"But it gives you extra motivation this year, tasting defeat sometimes. I've been here a few seasons now and I've been on that winning side a lot, and I'd never felt a loss in a grand final.

"So now I have, and I think it just makes you appreciate the wins and gives you that hunger to create more success again."

Retre believes the new rivalry and increased competition between his club and City is positive for Australian football.

"It's good, it's only good for the A-League when you're having clubs like Melbourne City there, a big club in terms of their resources," he said.

"For them, it was a good win. But we know what it's like, it's harder to stay there at the top because they're the hunted now.

"We know what we have to do to do well this season. Everyone's very motivated to go one step further this season and bring back some success to Sydney."

A fullback or midfielder, Retre joined the Sky Blues from City in 2017. The 28-year-old Victorian has won two premierships and two championships at the club, along with an FFA Cup.

But the former Young Socceroo says there is still more silverware to be won by his team, with adding to the trophy cabinet the clear goal once again.

" That's Sydney FC's challenge every year," he said.

"The last five years we've been first, second, first, second. So that just shows the intention of the club every single year is to win trophies and be challenging at least.

"That's our goal and it's obviously going to be difficult with a lot of teams wanting to vy for the same honours. Sydney FC's style is to bring in quality players and I think they've done that this season too.

"Going forward we've brought in some quality and to add to the existing players we've got already, so there's a good mix at the moment."

Retre has now made more than 140 career appearances in the A-League and has excelled in the Harbour City.

"I've thoroughly enjoyed my time at Sydney FC," he said.

"Looking back on it now I didn't think I would be here so long. It's been such a great journey for me and I really love the club."