ST KILDA big man Rowan Marshall has been rewarded for an encouraging 2018 by being upgraded to the senior list.

The New Zealand-born tall played 12 games this year, showing promise in the ruck and attack, despite booting an inaccurate 6.13.

Marshall has spent the past two seasons on the rookie list, and his work ethic hasn't gone unnoticed at Moorabbin.

"Rowan's worked hard to prove himself at the top level since coming in as a rookie," head of list management James Gallagher told saints.com.au.

"We're really happy with his progress as a footballer, and he showed some really promising signs when he came into the senior side this year.

"To be elevated to the senior list is a good indication of how far he's come during his two years at the club, but he'll continue to work away and aim to play more senior footy in 2019."

Marshall has played 13 career matches after making his debut in round 18 last year against Sydney, and averages 13 disposals.

The 22-year-old could be leant on for more ruck support next season after the Saints traded Tom Hickey to West Coast.

St Kilda shored up its ruck department by signing big men Billy Longer and Lewis Pierce to one-year deals earlier this week.