GREATER Western Sydney's greatest shield in its ongoing player retention battle has been the promise of sustained on-field success.

Those who left the Giants’ lair risked missing out on multiple premierships given the phenomenal talent they had stockpiled through unparalleled draft picks and start-up concessions.

But that protection has been battered by the unprecedented player exodus that unfolded over this year's NAB AFL Trade Period as the Giants moved to slash more than $2 million from a wildly overflowing salary cap.   

Consider the magnitude of GWS' losses, all of them contracted players:

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The only comparable player exodus in recent memory was that at Essendon in 2002 when stifling salary cap pressure forced the Bombers to trade 2000 premiership heroes Blake Caracella, Justin Blumfield and Chris Heffernan. 

The Dons, who finished 2002 in fifth, were never serious contenders again in the remainder of the Kevin Sheedy-James Hird era, and have not won a final since 2004. 

In fairness, GWS appears far better placed to absorb its exodus.

Its senior core of Callan Ward, Phil Davis, Stephen Coniglio, Josh Kelly, Toby Greene, Jeremy Cameron, Lachie Whitfield, Nick Haynes and Zac Williams remains the equal of any in the competition and Tim Taranto, Jacob Hopper, Harry Himmelberg and Aiden Bonar are elite young talents.

Further, GWS is well placed to unearth more prodigies with the picks it brought in through the Shiel and Lobb trades – numbers 9, 10 and 19 this year, as well as Essendon's 2019 first-round pick.

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As talented as the Giants' list remains, however, their depth has been smashed following the exits of Shiel, Scully, Lobb and Setterfield.

Giants football manager Wayne Campbell had a busy Trade Period. Picture: AFL Photos

Will they be strong enough to again contend next season – especially if this year's injury curse continues – or is their shot at a premiership with the nucleus of 2012's foundation list effectively over?

That will be the question on the minds of Giants stars Kelly, Coniglio and Haynes when they contemplate whether to re-sign beyond their existing tenure of 2019. 

Kelly's manager, Paul Connors, said last year he was "obsessed" with his clients winning premierships, adding: "I think Greater Western Sydney has got a pretty good list and have a good future." 

When he and Kelly sit down to discuss his post-2019 future, Connors – and, more importantly, Kelly himself – couldn't possibly be as bullish about the Giants' premiership prospects as they were when Shiel, Lobb and Scully were still in western Sydney. 

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Add the fact Ryan Griffen is also gone, with Heath Shaw and Brett Deledio almost certain to follow him into retirement at the end of next season, and that inevitable flag looks less and less likely.

When rival clubs come calling again – and that process would have already started – will Greater Western Sydney's shield of assured success be damaged beyond repair?

Only time will tell and that's why 2019 shapes as a crucial year for the Giants.

If they can show early in the season that Shiel, Lobb, Scully and Setterfield did not shut the premiership window on their way out, their hopes of convincing Kelly, Coniglio, Haynes and co. to stay rise exponentially. 

If they can't, they could be in for another exodus. 

And this one won't raise questions about their immediate flag hopes, it will snuff them out completely.

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