IT APPEARS a race in three for Caleb Marchbank, with Carlton, St Kilda and Essendon circling the wantaway Greater Western Sydney defender.

Greater Western Sydney announced on Thursday that Marchbank had requested a trade and, as speculated for much of this season, it is understood the Victorian wants to join a club in his home state.

The 19-year-old has struggled with homesickness for much of his two seasons in western Sydney, and was open with GWS this year about potentially wanting to move back to Victoria. 

It is believed the Giants recently asked Marchbank to make a call on his future given the injured defender won't be a part of their inaugural finals campaign.

The club's list management team also wanted to get a jump on what shapes as a busy trade period, with out-of-contract players Jack Steele and James Stewart, and contracted players Will Hoskin-Elliott, Adam Tomlinson and Cam McCarthy all linked to rival clubs. 

Carlton, St Kilda and Essendon have been closely monitoring Marchbank's situation all season.

Although other Victorian clubs could now seek to throw their hats in the ring for the defender's services – potentially clubs like the Western Bulldogs and Collingwood, who both made strong but unsuccessful bids for Essendon backman Michael Hurley – it is likely they have left their runs too late.

Marchbank joined the Giants via pick No.6 in the 2014 NAB AFL Draft and it is expected the expansion club will put an equivalent trade price on the youngster's head.

Rival clubs suspect Carlton leads the race for the former Murray Bushranger. The Blues have pick No.5 in this year's draft, but could be reluctant to part with that selection given their desire to keep investing in the draft and their interest in Gold Coast midfielder Jaeger O'Meara.

Essendon won't part with the prized first pick in this year's draft and, if the Bombers' play for O'Meara founders, they could seek to acquire Marchbank for free with the first pick in the pre-season draft.

St Kilda has draft pick No.10 but traded its second-round selection to Collingwood last year for Nathan Freeman.

GWS said simply in a club statement on Thursday that it would "now endeavour to complete a trade that is beneficial to the club".

Marchbank played just two senior games this year because of ankle and shoulder injuries, and has not played since dislocating his shoulder in the NEAFL in July.

He played just seven games in total with the Giants, but showed enough in his two seasons with the club to suggest he can develop into a quality and combative key defender. 

The Giants acquired the draft pick that secured Marchbank in their 2014 trade with the Western Bulldogs that sent Ryan Griffen to GWS and Tom Boyd to the Whitten Oval.