Assistant coach Henry Playfair believes Harry Marsh's inclusion ahead of Saturday's clash with Richmond is a testament to the defender's doggedness.

Marsh, one of eight players to debut for Sydney this season, was welcomed back into the side on Thursday as one of two changes ahead of the Round 23 encounter against Richmond, a crucial game which will shape whether the Swans cement the minor premiership and an all-important home final.

The 22-year-old featured three games earlier in the season but was struck down with a hamstring strain during the loss to GWS in Round 12. He was sidelined for six weeks before stringing four strong performances together for the NEAFL Swans.

Playfair said the recall was just reward for Marsh's determination and persistence.

"He's a guy that worked hard, regardless of the situation," Playfair said.

"Even in our pre-season training sessions he'd front up every week and give it everything he got.

"That's what I'm looking forward to seeing (on Saturday) more than anything."

Marsh's versatility, Playfair added, will be an asset to a defensive six which will be without Callum Mills who has been sidelined with a calf complaint.

Sydney's back half has conceded the least amount of points of any club this season, despite going through personnel changes at different stages throughout the season.

Instead of rocking the boat even more, Playfair expects Marsh to bring the same level headedness in his three consecutive games earlier in the year.

"(Harry) can play tall and small," Playfair said.

"He defends really well, he's got good pace to shut down leads, uses his pace with the ball, goes pretty direct when he gets the footy so I'm sure he'll have no probelm slotting straight in."

"As a coach, I was apprehensive before his first game. Coming in against North Melbourne, who were undefeated at that stage, at the SCG in front of a full house.

"But he handled it with real composure so I'm expecting the same thing from him again."

Marsh joined Kieren Jack as the two inclusions for the twilight fixture, the final game of the home and away season, replacing Mills and Dean Towers (omitted).