After playing just three games in 2017, Sydney defender Allir Allir could soon become an important piece in the Swans' game plan for 2018.

Allir broke into Sydney's best 22 during his debut season in 2016, and played 13 games that season with his blistering run out of defence and strong marking presence his best attributes.

The 23-year-old played the first three games of last season but was dropped in round four and didn't return, although coach John Longmire told AFL.com.au he struggled to break into the side last year because of a pre-season turf toe injury.

"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 coach believes Allir is an important member of the side and will break back into the team this season, although a new role could be on the cards.

"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."

Allir's opportunity in the side comes after Kurt Tippett's retirement, with the key-position veteran calling time on his career earlier this month after failing to recover from his latest ankle injury.

Longmire understands Tippett's loss would be a big one, although is confident the Swans have the tools to adequately replace him.