Sydney coach John Longmire has backed his inexperienced AFL ruckmen and revealed he may use a couple more youngsters to pinch hit while Callum Sinclair and Kurt Tippett are sidelined.

Sinclair and Tippett will miss multiple matches for the third-placed Swans, leaving Sam Naismith, 24, (four senior games) and 21-year-old Toby Nankervis (eight), to shoulder the majority of the ruck work.

“We’re really confident in what they’ve been able to do, they are two young players that have shown promise,” Longmire said on Thursday.

Tippett has been out for five matches after undergoing hamstring tendon surgery and is on track to return in round 22.

Sinclair is recovering from arthroscopic surgery on the right knee he injured against Carlton last weekend, but Longmire said he should be back before the end of the season.

Naismith made just one senior appearance before this season but has played the last three games and racked up career-best numbers in virtually every major statistical category last weekend.

“He’s grown in confidence, his ruck stuff has been very important for us and particularly his centre bounce work,” Longmire said.

“His ability last week to ruck against Matty Kreuzer was of a pretty high standard.”

Nankervis, who is expected to replace Sinclair against Fremantle in Perth on Sunday, was one of the Swans’ best in their NEAFL team last week when the more experienced Tom Derickx didn’t play.

“We’ve certainly got the option to try different options as well in regard to maybe (defender) Aliir Aliir (five senior games), (forward) Xavier Richards (three),” Longmire said.

“Those guys we might look at in coming weeks.

“Aliir has done a bit of ruck work for us in the reserves and also as a junior.

“He’s got an enormous leap, we know he’s really improved.

“Xavier has done a little bit, not a lot. We’ve used Dean Towers in that role as well, so we feel as though we’ve got a few options.”

Longmire noted around half the Swans side to contest Sunday’s game would be different to the one that played the Dockers in a finals game in Perth just under a year ago.

He said playing in Fremantle icon Matthew Pavlich’s 350th AFL game was a fantastic opportunity for the Swans youngsters, many of whom have not played at the venue before.

Longmire had no doubt Pavlich made the right decision to play on this year.

“Absolutely he should have, he’s had a really good year,” Longmire said.