ST KILDA has rewarded New Zealand-born key-position prospect Rowan Marshall with a two-year contract.

The 21-year-old joined the Saints with pick 10 in last year's NAB AFL Rookie Draft after a striking VFL season for North Ballarat.

Marshall kicked 22 goals in 16 VFL games this season for Sandringham and impressed enough to be elevated to the senior list mid-year and earn an AFL debut against Sydney in round 18.

The 201cm ruck-forward, who has also spent time in defence, won 14 disposals and had five hit-outs that night.

St Kilda is yet to decide whether Marshall will be on the primary list next season, but chief operating officer Ameet Bains said he had "a bright future".

"Being a bit older, he was better placed to cope with the increased training demands and professionalism required at the elite level," Bains said.

"Early on in the season, he was quite dominant as a forward for Sandringham, where his clean hands and contested marking were a feature.

"As the season wore on, he also showed his potential to hold down a key defensive post. With another strong pre-season under his belt, we are confident he can improve again in 2018."

Marshall's signature follows that of fellow youngsters Jack Billings, Jade Gresham, Luke Dunstan, Jack Sinclair, Jimmy Webster, Brandon White, Tom Hickey, Ben Long, Bailey Rice and Daniel McKenzie in the past 12 months.