NICK Riewoldt has played footy at its highest level for 17 seasons, desperately wants to make it 18.  

He's 34, turns 35 in October, and his troublesome knees are as banged up as ever.  

One of those knees now has bone grinding on bone, forcing the six-time St Kilda best-and-fairest to the sidelines at least for a fortnight, possibly for three weeks or more.  

For him, the doubt over his knees is something he has successfully managed for at least half of his extraordinary career.  

But that doubt is now a far from ideal backdrop as he and his management begin long-planned talks with Saints officials about a new contract. It is a situation which does not help his case to be a listed player in 2018.

For the Saints, and they won't admit this publicly, that doubt works in their favour. For them, there is no reason to unconditionally commit right now to a future with Riewoldt.  

St Kilda enters its bye weekend with a 5-5 scoreline and losses in the past two weekends via ordinary performances against Western Bulldogs and Sydney.  

As he has done for most of the eight games he's played in 2017, Riewoldt played well against the Swans. In those eight matches, he's booted 17 goals, averaged 19 disposals and averaged seven score involvements. They are more than sound numbers for a player wanting to continue into next year.  

Riewoldt missed the Bulldogs game because of the knee injury. A decision on his availability to play an away match against Adelaide in round 12 is yet to be made, but he is doubtful.  

The self-driven St Kilda hype and hopes for season 2017 is still there, but clearly the club knows it needs to recruit opposition stars.  

Cleverly, they have gained access to two first round picks in the next national draft. Even more cleverly, they have, within the rules, manipulated their salary cap to the point where they have freed up more than $1.5 million of extra space for the 2018 season.  

That has allowed them to aggressively attack the player market, and conversations with people representing Nat Fyfe began more than a year ago. So too with Josh Kelly and Lachie Whitfield.  

The already-guaranteed $1.5 million of extra salary cap cash would become a whole lot more should Riewoldt and Leigh Montagna, 34 in November, not continue beyond this year.  

Should both ageing stars finish, the Saints would be in a financial position to land two guns on $1 million each per year contracts.  

Does one of Riewoldt and Montagna stay, and one go? Do they both go? Do they both stay?
Jack Billings, Nick Riewoldt, and Leigh Montagna sing the song in round seven. Picture: AFL Photos 

They are tough, highly contentious, emotive calls, no matter the outcomes.  

St Kilda has called time on favourite sons in the past, including great mates of Riewoldt and Montagna in Nick Dal Santo and Brendon Goddard.  

And, just as North Melbourne did last year with Brent Harvey, Drew Petrie, Nick Dal Santo and Michael Firrito, St Kilda is emotionally wrestling with the situations around their ageing stars.  

Riewoldt and Montagna have both had multiple lucrative offers to leave the Saints, Riewoldt as recently as late 2013 when Collingwood president Eddie McGuire made a significant pitch, and the ageing stars are well within their rights to believe the Saints owe them one last year of football.  

"I'm still really keen to contribute to the football club, my best footy this year has still been really strong, and that conversation will begin around the bye," Riewoldt said on Triple M on the weekend.  

"That tends to be when list committee meetings tend to happen. I'm certainly not banging down their door saying I need to know tomorrow."  

As Riewoldt and Montagna are in their pitch to seek fresh deals, St Kilda is comfortably within its rights to leave these decisions until after the final game of 2017, whenever that is.  

Brent Harvey thought he could play forever and his form in 2016 more than warranted a contract for 2017.  

While Harvey would be justified in thinking he would still be among the weekly best players for the Roos this year, the club says that without him being part of it, there has been clear development in Trent Dumont, Luke McDonald, Taylor Garner, Mason Wood, Ryan Clarke and Kayne Turner, as well as increased levels of responsibility assumed by Shaun Higgins, Jack Ziebell and Jamie Macmillan.  

While North was always entitled to make that decision and now publicly state it was right in so doing, it knows it totally and embarrassingly botched aspects of it, mainly the negative impact it had on the looming finals series and in failing to adequately plan its own public messaging once the decision was made.  

St Kilda, Riewoldt and Montagna are now thrashing out their moves.  

No matter what happens, there are lessons – good and bad, right and wrong – for all parties to heed from North Melbourne last year.  

Twitter: @barrettdamian