Back in the not-too-distant past, when the Jets were performing an uncanny impersonation of a dysfunctional rabble, their nearest neighbours were arguably the A-League's benchmark franchise, judging by on-field results on a dollar-for-dollar basis.

Sure, the Jets claimed endless bragging rights for a certain 1-0 victory at Sydney Football Stadium in February, 2008, but the euphoria was fleeting.

Central Coast's highlights, in contrast, were more consistent and over a sustained period.

In the first nine seasons of the A-League, they qualified for the play-offs seven times, won two minor premierships, reached four grand finals and celebrated one championship win, in 2012-13.

For the first eight of those campaigns, they had only two coaches, Lawrie McKinna and Graham Arnold, whose teams regularly upstaged and dominated rivals with far bigger budgets and more illustrious players.

Somehow the Mariners - the A-League's smallest club, in terms of corporate support, crowd numbers and the size of the community they represent - kept defying the odds stacked against them.

But fairytales are few and far between in modern-day professional sport, and reality inevitably started to kick in.

By March 2013, when businessman Mike Charlesworth increased his stake in the club to 64 per cent, hence becoming the majority owner, the Mariners were already experiencing financial difficulties.

They made the play-offs that season but have not managed to since.

After last week's 8-2 thrashing from Wellington, which left them with just one win from 21 games this season, they now appear certain to receive their second consecutive wooden spoon, and third in the space of four years.

Unless they can salvage some pride over their last six games of 2018-19, they are on track to finish with an unwanted record - the most goals conceded in a single A-League season by any team.

Last week's hammering cost coach Mike Mulvey his job, and his replacement, Alen Stajcic, will be Central Coast's fourth head tactician inside the space of a year.

At McDonald Jones Stadium on Saturday, they will need a miraculous form reversal to prevent Newcastle from racking up a record sixth consecutive victory against their traditional rivals.

And at this particular juncture, I can't help wondering if the 47^th F3 derby will be the last.

That might sound alarmist, even fanciful, but it will perhaps strike a chord with fans of now-defunct North Queensland Fury, Gold Coast United and New Zealand Knights.

Sometimes there comes a point when those responsible for funding a struggling club concede that it is beyond salvation and has become unsustainable.

Charlesworth, an Englishman who made his fortune in the telecommunications industry, has attracted increasing criticism for his apparent reluctance to invest in the playing roster.

I have seen his management approach described as "cynical" in some reports.

Yet given that he has presumably spent millions propping the club up already, is it really fair to ask him to dig deeper?

 As fans of the Newcastle Jets and Knights are well aware, even billionaires - or alleged billionaires - do not always have access to a bottomless pit of cash.

If Charlesworth did decide that enough was enough, and walk away as so many other A-League franchise owners have done in the past, the real worry is whether anyone would be interested in stepping in to replace him.

A poorly performing sporting club, in a small and geographically challenging marketplace, does not strike me as hot property. 

The Mariners are a reminder that the A-League, as a whole, is in a rather precarious position.

Former three-time champions Brisbane Roar are also floundering, and their past four games at Suncorp Stadium have all attracted crowds of less than 8500.

This time last season, Wellington Phoenix were on the endangered-species list.

Meanwhile, the competition is set to expand next season, and again the season after, regardless of how well the current clubs are performing.

Moreover, there is a growing push for the A-League to abolish the salary cap, which would surely only increase the advantage the richer clubs already enjoy over their less-affluent rivals.

The other concept gaining widespread support is the introduction of a promotion-relegation system, but how long then before we would return to the days of the National Soccer League, playing games at second-rate suburban grounds instead of modern stadiums?

The bottom line is only the most parochial of round-ball aficionados could declare with any confidence that the A-League is guaranteed a bright and prosperous future.

Even fewer would bet their bottom dollar that the once-proud Central Coast Mariners will be a part of it.