DURABLE Sydney defender Nick Smith concedes his career could be over if his latest operation fails to fix his troublesome hamstring.

Smith hasn't played since he ripped his hamstring tendon away from the bone against Melbourne at the MCG in round 21 last year.

His body has rejected repeated attempts to get back to full training this season.

If I was the club, I mean I'm 31 and I haven't played for a year, I wouldn't call it a risk, but do they give a young guy an opportunity (instead)? - Nick Smith

In eight seasons prior to this year, the premiership Swan and 2014 All Australian had averaged almost 23 matches a year.

The veteran managed to rehabilitate his dodgy hammy multiple times to the point where he could run in straight lines at moderate intensity, but every time he tried to push himself further, he was forced to back off.

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Sydney's medical staff consulted specialists last month and it was decided more surgery was needed, which ended Smith's 2019 campaign.

Nick Smith leaves the field during last year's R21 clash with Melbourne. Picture: AFL Photos

Out of contract at the end of the year and still 4-5 months away from knowing if the operation was a success, the 31-year-old said he was confident he could play on in 2020, but that decision would be out of his hands.

The Swans lost Heath Grundy to retirement earlier this season and, with doubts lingering over the futures of Jarrad McVeigh and Kieren Jack, Smith knows there is a changing of the guard at Sydney. Even if he can get back on the field, there might not be a spot for him.

Veteran defender Heath Grundy says farewell to Sydney fans in round 12. Picture: Getty Images

"If the club still wants me and I can still go around again, good. If not, then that's life," he said.

"If I was the club, I mean I'm 31 and I haven't played for a year, I wouldn't call it a risk, but do they give a young guy an opportunity (instead)?

"It probably depends on how the side is going. There [are] a lot of balls up in the air at the moment so we'll just figure it out at the end of the year.

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"There's still plenty of unknowns but I'm pretty easy with that at the moment.

"If you're mentally ready and your body holds up, then why should age be a reason as to why you shouldn't play?

"I saw (Western Bulldogs defender) Dale Morris is 36 and he said the same thing (this week)."

While Smith's career remains in limbo, speculation over the future of John Longmire continues to build after a forgettable week of media appearances for the Sydney coach.

Since Brad Scott departed North Melbourne in May, Longmire's name has been linked to the role at his old club, despite being contracted to the Swans for 2020.

Speaking on Fox Footy just hours after he brushed off questions about the issue at his weekly news conference, Longmire's stumbled comment that he was "absolutely contracted to the North… to the Sydney Swans football club" certainly raised eyebrows.

Smith said the Swans players weren't bothered by the gaffe and had plenty of fun at Longmire's expense.

"His slip-of-the-tongue was pretty funny. The boys enjoyed that," he said with a laugh.

"I think even Dane Rampe, who's had a few of his own this year, said 'what's going on there?'. Who knows what's going to happen, I honestly have no idea.

"All I do know is the club is committed, 'Horse' is committed, and the players are committed to this year, and beyond that, it'll sort itself out."