NEWLY re-signed defender Nick Smith epitomises everything the Sydney Swans want their players to be, according to coach John Longmire.

Smith, 27, was set to be out of contract at season's end, but has agreed to an extension with the Swans that will keep him at the club until at least the end of 2018.

The former rookie has played 142 games for the Swans since making his debut in 2008, and has become one of the most consistent and reliable small defenders in the competition.

Often opposed to the most dynamic small forwards in the League such as Hawthorn's Cyril Rioli and Adelaide's Eddie Betts, Smith has played at least 21 games over the past five seasons.

Speaking exclusively to AFL.com.au Longmire said Smith's value to the Swans was immeasurable.

"He's just a wonderful person, he's very humble, drives the group, and is absolutely driven," Longmire said.

"He's a really underrated player who plays on the best small forward every week, and gets the most out of himself every session, every day, and is a great example for younger players coming into our club.

"Nick is always trying to get better and you know you've got a player who every time you send him down the race, is going to give it his all.

"He doesn't leave anything to chance and that's what makes him so good."

Smith's contract extension is another significant deal for the Swans, after gun midfielder and 2012 premiership teammate Luke Parker re-committed to the club last week.

Like Parker, the 2014 All Australian back pocket refused to deal with anyone but the Swans, and Longmire said the duo were extremely similar in the way they go about their lives on and off the field.

"Both of them are in our leadership group, are extremely strong characters, and fantastic people first and foremost," Longmire said.

"They get the most of themselves and their football speaks for itself on the weekend, but as far as people go, they're 'A-grade'."

Smith told AFL.com.au he was "absolutely stoked" to be offered two more years at the Swans, the club he arrived at almost a decade ago after being picked in the 2007 NAB AFL Rookie Draft.

With club legend Adam Goodes, plus fellow 2012 flag winners Rhyce Shaw, Mike Pyke, Lewis Jetta and Craig Bird all leaving the Swans at the end last season, Smith's experience will be vital this year.

The uncompromising backman said the Swans' famed culture would help the club adjust to life without those stars.

"The people inside the club are the best thing about it, and the people who have come before me as well," Smith said.

"I was fortunate enough to have the likes of 'Kirky' (Brett Kirk), Leo Barry, Mick O'Loughlin, Craig Bolton, Barry Hall, and even now with John Longmire and the assistant coaches, we've got a really good mix of people at the Swans.

"I think that's how it works, you get taught by the people before you and hopefully you can pass that onto the younger guys.

"It's the funny thing about football clubs that you just move on, obviously you miss those guys around the rooms and that sort of thing but you get new guys in.

"Guys like Isaac Heeney and Callum Mills come in and the footy club is always evolving.

"What it does give is not only opportunities to young guys to play, but also from a leadership point of view."