Aliir Aliir shapes as a possible replacement for retired tall Kurt Tippett, with the Swans considering trialling the key defender as a support ruckman.

After a breakthrough 2016 season in which he cemented a position in the Swans' defence, Aliir endured a tough 2017.

Dropped after the Swans' round four loss to West Coast, he did not play another senior game for the season.

Aliir had been recalled for Sydney's round seven clash against the Brisbane Lions, but blew that opportunity when he missed a training session the day before the game. Thereafter, rookie Lewis Melican's solid form alongside Heath Grundy and Dane Rampe in the Swans' backline kept him out of the side.

Swans coach John Longmire told AFL.com.au Aliir's difficult 2017 season could largely be explained by a case of turf toe he suffered during the pre-season, which prevented him from running for three months.

"It was a pretty significant injury and that really set him back a bit. Then when he started to get going, Lewis Melican had got a start in the team as a key defender, we were on a bit of a winning roll and it was hard for Aliir to get back in the team," Longmire said.

The Swans coach is confident Aliir can force his way back into Sydney's best team in 2018, but is keeping an open mind on where he'll be played.

"We think he can really add to our team but we're keen to get him back in that form he was in two years ago, whether that's down back or in other roles. We're keen to see Aliir really grab those opportunities," Longmire said.

"We think he can play as a key defender, but also a third tall role and give us some more rebound and punch from our back half. We think he can also play in the ruck as a second ruck and give us some real mobility around the ground.

"Ultimately, it will be determined by form and what roles are there – he just needs to grab them."

Tippett retired earlier this month after 178 AFL games because of chronic ankle injuries.

Longmire said the 30-year-old would be a significant loss, but was confident Sydney was well placed to replace him.

The former Crow played just nine games in 2017 and neither of the Swans' two finals, in which time Sam Naismith and Callum Sinclair ably shouldered most of the Swans' ruck duties.

Longmire also has high hopes for untried West Australian ruckman Darcy Cameron, while pointing out the Swans also successfully used one specialist ruckman at times last season with Dean Towers and, to a lesser extent, Luke Parker and Josh Kennedy all performing support ruck roles at stages.