What do Sol Campbell, Luis Figo, and Miloš Ninković have in common? They fill the not-so illustrious turncoat archetype; players that with one stroke of a pen abdicated their chances to become legends of their club and, at best, cast a cloud across their legacy.

In swapping Sydney FC for Western Sydney Wanderers, Ninković has arguably come as close as any in the A-League Men to rivalling Campbell’s move from Tottenham to Arsenal or Figo’s switch from Barcelona to Real Madrid. Plenty have played on both sides of the Harbour City in the past, but none have possessed the kind of legacy that the Serbian maestro has forged during his time at Moore Park.

Signed from Red Star Belgrade in 2015, Ninković won three championships, three premierships and an FFA Cup for Sydney, as well as scooping two Johnny Warren medals, an Alex Tobin medal and a Joe Marston medal. He sits comfortably amongst the pantheon of the club’s all-time greats and is arguably the greatest foreigner to lace up his boots in the competition. In all probability, Sydney’s dynasty would not have happened without him. Any separation was always going to be painful.

Yet now, having engaged in a seven-year love affair, Sydney fans will have to watch on as he pulls on the shirt of another. And not just any other. They will watch on after having their emotions played with for weeks, since Ninković posted a farewell message on Instagram only for the club to respond the next morning by saying that negotiations between player and club were very much ongoing – despite their social media managers posting a quickly-deleted farewell message of their own.

What followed was a tide of whispers linking the player with a move to bitter rivals Wanderers that ultimately became a cacophony.

Ninković said he would “never forget these years and I will also have a huge fondness and a strong bond with our members and fans”. But any such bond will evaporate quickly the first time he is seen taking orders from Mark Rudan in the next Sydney derby.

Sydney made clear that their efforts to keep the playmaker “included the offer of a new playing contract and a future role in player and game development”. The sentiment that Ninković has operated as a mercenary and thrown away his connection with the Sky Blues’ faithful, will likely permeate the fanbase.

Ninković lifts the A-League Men trophy.
Ninković lifts the A-League Men trophy. Photograph: Cameron Spencer/Getty Images

From a narrative perspective, it’s top stuff. It’s difficult to see, with early-season derbies now an established trope of the competition, how league operators fail to take advantage of the acrimony and schedule a Sydney derby in the opening weeks of the season. Indeed, it’s not inconceivable that the Sky Blues could mark their first ALM game at the new Sydney Football Stadium against Ninković’s Wanderers. The man that months prior deserved a statue outside the venue will now be opening it in the colours of the enemy.

Yet, what of the actual football? How does 37-year-old Ninković fit into the plans of Rudan and the Wanderers? He clearly thinks he can still contribute. At his best, the Serb remains a nightmare for opposition. Age arguably caught up with his legs years ago but his mind remains as sharp as ever. His lack of speed can be obscured by an innate sense of positioning and anticipation and he possesses a sense of gravity on the field; defences are pulled in his direction.

Nonetheless, Father Time is undefeated and, eventually, his grip on Ninković will tighten. What role he is expected to take at CommBank Stadium and his responsibilities on the pitch, will dictate the ramifications. This conundrum is likely why Sydney, at the crossroads of their own rebuild, were not as proactive in their attempts to retain Ninković. These are the hard decisions football clubs make.

History may validate them for this. The Wanderers have lost the benefit of the doubt when it comes to rebuilds, but that won’t stop the first-time Ninković lines up in opposition being a bitter pill for Sydney FC to swallow. And if silverware should follow him to Sydney’s west, a sense of melancholy amongst the Sydney fanbase will likely turn to anger, pointed outward and inward.