St Kilda has made wholesale changes following the disappointing 61-point loss to Essendon last weekend, with five players coming in for the trip to Sydney, including a debutant in Rowan Marshall.

Ruckman Billy Longer returns after missing last Friday night due to a hamstring strain, as does defender Jimmy Webster after serving his two-game suspension, while midfielders Luke Dunstan and Blake Acres have been rewarded for strong form in the VFL.

After being elevated off the rookie list last week and named as an emergency against the Bombers, mature-age recruit Marshall will become the third Saint to debut this season when he faces the Swans at the SCG on Saturday night.

After two seasons in the VFL with North Ballarat, the 21-year-old from Portland was selected with pick No.10 in last year's Rookie Draft.

Marshall has produced a consistent season under Lindsay Gilbee's watch at Trevor Barker Oval, playing all 12 games predominantly as a tall forward, along with bursts in the ruck.

Stalwart defender Sam Gilbert is the only forced change ahead of the AFL's second Pride Game, with Tom Hickey, Ben Long, Daniel McKenzie and last week’s debutant Josh Battle all left out of the side to face the in-form team in the competition.

After falling heavily last Friday night in a performance Alan Richardson labelled as 'embarrassing', the task doesn’t get much more difficult for St Kilda.

The Swans have overcome a 0-6 start to the season to amazingly emerge as a genuine premiership contender after winning nine of their past 10 games.

John Longmire's men have a commanding record over the Saints in recent years, winning the last seven encounters dating all the way back to 2012.

While the Saints haven't won at the SCG since 2009, they should take confidence from their recent form on the road, having beaten Fremantle at Domain Stadium three weeks ago, and Hawthorn at University of Tasmania Stadium in May.

Round 18 Team v Sydney
Saturday July 22 at 7.25pm
SCG

B: Jarryn Geary, Nathan Brown, Dylan Roberton
HB: Jack Newnes, Jake Carlisle, Shane Savage
C: Leigh Montagna, Koby Stevens, Jack Billings
HF: Jack Sinclair, Nick Riewoldt, Jack Lonie
F: Jade Gresham, Josh Bruce, Rowan Marshall
R: Billy Longer, Seb Ross, Jack Steven
Interchange: Luke Dunstan, Blake Acres, Jack Steele, Jimmy Webster
Emergencies: Ben Long, Brandon White, Jason Holmes

IN: J. Webster, B. Longer, L. Dunstan, B. Acres, R. Marshall
OUT: S. Gilbert (hand), T. Hickey (omitted), D. McKenzie (omitted) B. Long (omitted), J. Battle (omitted)