Cape Town - Brace yourselves ... barring an unlikely U-turn in current, charitable SA Rugby selection policy, the Springboks of 2020 onward will, for the first time in history, consistently be characterised by a marked dominance of overseas-based players in the starting line-up.
That is becoming increasingly apparent as the wave of mid-career - and now often younger than that, too - defections of staple national players to more lucrative foreign climes mounts with worrisome menace.
Although you have to be cautious about forecasting national selection further up the line, especially as the country should remain a strong producer of fresh-faced talent, so many proven international-class Boks are already plying their trades on the opposite side of the Equator, and about to be joined by many others, that home-stationed players seem almost certain to become a novel minority in the Test match-day squads from next year.
In fact, depending on further shockwaves on the "brawn drain" front, if you like, in the next few weeks and months ahead of completion of another RWC cycle, an optimal-strength Bok side from 2020 could feasibly feature SA-based representation of as low as a third or a quarter of its ranks.
Flyhalf Handre Pollard and centre Jesse Kriel are just two further, notable green-and-gold regulars of the Rassie Erasmus head-coaching tenure, and a bit before it, to have been confirmed this week as quitting the Bulls after this season to further their professional careers abroad - Pollard with Montpellier and Kriel at Japan-based Canon Eagles.
Both are only 25, so with the lion's share of their high-level rugby careers still ahead, fitness provided.
Pollard is well clear of any other South African pivot as the premier Bok in his berth as things stand, and Kriel is also now holder of 40 Test caps - predominantly at outside centre - even if he faces a stiff challenge from the Sharks' Lukhanyo Am for the No 13 jersey in this World Cup year.
Similarly, someone like Sale-bound second-rower Lood de Jager, who at 26 also has years of promise ahead and at very least two further World Cups in him, could well yet make himself "undroppable" if he starts getting better luck on the injury-related front.
On that score, lock is increasingly primed to be the berth that most notably demonstrates the dramatic shift of best SA resources to foreign pastures after 2018.
On the reasonable assumption (though again it could change) that the quartet of Eben Etzebeth, RG Snyman, De Jager and Franco Mostert will remain perhaps the cream of options there for the Boks for some time to come - none of them are creaking veterans, by any stretch of the imagination - all would have to be summoned from abroad to the Bok fold next season.
Virtually routine top national choice Etzebeth, after some eight years of availability to the Stormers in Super Rugby (though the competition has often rather jinxed him in terms of enforced layoffs) is Toulon-bound from 2020 although at current age 27 he should remain an indispensable Test figure.
Mostert is now on the books of Gloucester, while the towering Snyman, such a revelation in his maiden exposure to international rugby last year, will abandon Loftus for the Honda Heat in Japan next year.
Just how extensively the best Bok material, all round, will be drawn from overseas from 2020 will also depend on just how successful - or otherwise - the Stormers are in retaining the services of their notable fulcrum of recent Test pack personnel.
The situation badly aggravated by the much-publicised cash crisis afflicting WP Rugby - there is other turbulence in the corridors of Newlands, too - the Western Cape franchise remain in grave danger of surrendering, after completion of Super Rugby 2018, the majority of their biggest forward names.
All of national and franchise captain Siya Kolisi, Etzebeth, Frans Malherbe, Steven Kitshoff and SA Rugby player of the year Pieter-Steph du Toit end their latest contractual obligations at Newlands shortly, although it is understood earnest moves are afoot to soften the imminent blow by clinging onto one or two of that group (Kitshoff and Du Toit, most likely?) for a bit longer.
Just between that group of five, there are a massive 228 Springbok appearances and no special likelihood that any are suddenly going to be deemed surplus to green-and-gold requirements after RWC 2019.
But in the worst-case scenario of all five shifting "north", the Bok team from 2020 really would have a high potential for containing a mere sprinkling of players whose franchise loyalties remain local.
Hardly helping is the likelihood that the famously SA-loyal (and to the Sharks, especially) Tendai Mtawarira - he of 107 Test caps and aged 34 by the end of the World Cup - will quit the international scene after it.
Just one further method of weighing up how the Bok side could be necessarily skewed in favour of overseas players after this season, would be to examine the starting XV from Erasmus's last Test in charge, the 20-11 Cardiff defeat to Wales at the end of the 2018 campaign, ticking off which representatives are already northern-based and the others now threatening to be so.
This was the line-up: 15 Willie le Roux, 14 Cheslin Kolbe, 13 Jesse Kriel, 12 Damian de Allende, 11 Aphiwe Dyantyi, 10 Handre Pollard, 9 Embrose Papier, 8 Duane Vermeulen, 7 Pieter-Steph du Toit, 6 Siya Kolisi, 5 Franco Mostert, 4 RG Snyman, 3 Frans Malherbe, 2 Malcolm Marx, 1 Steven Kitshoff.
It is at least a partial, sobering indicator of the looming, potentially enormous change in Bok "local v abroad" staffing ratio, don't you think?