Sydney FC are set to make a number of player signings this week as coach Graham Arnold looks to build on the best season in A-League history.

Less than 24 hours after the Sky Blues sealed a stunning premiership-championship double, the notoriously high-achieving Arnold is already making moves to replicate the success next campaign.

The first step has been keeping his record-breaking squad, a shrewd move reminiscent of Ange Postecoglou's swift retention manoeuvres after 2010-11, when his Brisbane premiers and champions famously backed up to take out the 2011-12 championship.

He also hinted at new faces.

"We've got some smart recruiting to do over the next three months," Arnold said.

"Most of the players are locked in for next season.

"There'll be a few signings announced this week."

Six of Arnold's starting XI are already signed in - goalkeeper of the year Danny Vukovic, defenders Rhyan Grant, Alex Wilkinson and Michael Zullo, along with key midfield pair Josh Brillante and Brandon O'Neill.

Alex Brosque's signature has long been a mere formality, and the in-form skipper has signalled he'll take whatever is left in the salary cap after the bulk of the squad is signed.

Meanwhile, club officials have been busy behind the scenes in recent weeks talking terms with the others still off-contract.

It's understood Brazilian striker Bobo has agreed to a one-year marquee contract extension and looks set to retain his $1-million salary.

And in a massive coup, Milos Ninkovic has given his strongest indication yet he'll stick around for a third season.

After slotting the winning penalty against grand-final opponents Melbourne Victory on Sunday night, the Johnny Warren Medal winner revealed "probably I will stay", a public confirmation of the club's quiet confidence in retaining the 32-year-old.

As one of the greatest imports the A-League has captured, Ninkovic is a shoo-in for Sydney's second marquee slot.

Should that occur, Slovak winger Filip Holosko would need to squeeze into the salary cap, which will rise from $2.6 million to at least $2.92 million in 2017-18.

Arnold is well-versed on the restrictions of such a frugal cap, one highly unconducive to keeping successful teams together.

Nevertheless, he was confident players would realise how good they had it in such a supportive and professional environment.

"The biggest thing for me has been building the culture and giving players everything," Arnold said.

"We have a chef that cooks the best meals for the boys and a fantastic training facility.

"Players will take unders to come to that type of culture.

"When players are cared for and looked after, and know they're going to improve their game and fitness, in a salary-cap system why would you take $20,000 extra to go over to the other side of Australia or to another club where you won't get that type of stuff?"