ST KILDA has zeroed in on former Collingwood defender Jonathon Marsh in a last-ditch bid to add much-needed defensive stocks for 2019. understands the Saints will put Marsh through a medical screening on Wednesday as they prepare for much of the season without star defender Jake Carlisle.

With Nathan Brown suspended for the season opener and concerns over Dylan Roberton, Marsh could make a shock AFL return in round one against Gold Coast should he be added to the list.

However, with the Saints hopeful of a late-season Carlisle return, they're expected to instead place injured draftee Jack Bytel on the long-term injury list – opening up a spot for Marsh. 

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Under new pre-season supplemental selection period (SSP) rules introduced this year, clubs have the opportunity to replace a player sidelined for the season before March 15.

Sydney moved quickly to replace injured defender Jack Maibaum to its list on Tuesday, plucking Hayden McLean out of SANFL club South Adelaide.

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It follows Carlton's recent move to add Williamstown dynamo Michael Gibbons and Dandenong Stingray Matthew Cottrell last month.

Marsh was due to play for Richmond's VFL side this season under former Collingwood assistant Craig McRae following two strong seasons for East Fremantle in the WAFL.  

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Marsh, 23, prematurely retired at the end of 2016 for personal reasons, however has recently signaled a strong intent to return to the top level.

During his 15-game career for Collingwood, the 194cm Marsh proved to be a competent intercepting mark across half-back.

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With Suns talls Peter Wright and Jack Lukosius looming in round one, Marsh could be thrust into spotlight with queries over the Saints' depth of talls.

Should Roberton miss, the key defensive posts would be left to Irishman Darragh Joyce, forward-turned-defender Josh Battle and Logan Austin, who played VFL on the weekend.

While Port Adelaide won't look to replace Jake Patmore before March 15, the Suns are expected to add a midfielder with one of three available list spots.

Other clubs with remaining list spots – Carlton, GWS, Hawthorn and Melbourne – will hold over positions for the mid-season draft in round 11.