Cape Town – Put in a consistently high work-rate, show some decent “ticker” … and it will be very hard for anyone else to expropriate your position.

That seems to be the earnest philosophy of Franco Mostert, who continues to only batten down more firmly his rights to the Springbok No 5 jersey.

The former Lions second-row stalwart, now plying his trade under Johan Ackermann’s tutelage again at Gloucester, certainly offered no evidence at all against Japan in Saitama on Friday that he is going to lose his status as first-choicer in his berth at the imminent World Cup.

Quite the contrary: the 28-year-old put in probably one his most thunderous, durable shifts in a now 32-Test career.

Mostert is hamstrung by a fairly widely-held perception – including by recent Bok lock legends like Victor Matfield and Kobus Wiese – that a combination of Eben Etzebeth (the staple No 4) and Lood de Jager, a standout figure whenever required for service during RWC 2015, may ultimately be the national team’s premier pairing.

It is not as though there is no truth to the assertion that De Jager, at best, is both a more naturally talented and physically gifted figure: even Mostert might just concede that he comes second for “X-factor” between the pair.

But selection isn’t solely based on that criterion, and it also a fact that De Jager isn’t quite yet back at his maximum prowess after an injury-curtailed 2019 season; he has been playing a gradual catch-up, while still more than warranting his spot within the broader Bok squad in the Far East.

There’s another formidable – yet also deceptively rangy, mobile – physical beast in the Bok lock armoury, in the shape of RG Snyman, who seems primarily earmarked as Etzebeth’s front lock understudy but is more than capable of operating at five, too … something he did plentiful times when sharing Bulls duty in Super Rugby with Jason Jenkins.

Still, Mostert is stubbornly and admirably refusing to budge, quelling any suggestions at present that the Boks could do better in his berth.

For the Sport24 Bok ratings on Friday, I had Mostert down as the best Bok pack member in the 41-7, Brighton-avenging victory over the Brave Blossoms, with a 7.5/10 score.

Always prepared to get stuck into the less noticeably glamorous areas of the game – like ruck cleaning, rugged assistance to mauls and rival maul-stoppage, tackling and getting over the ball at breakdowns – Mostert also ticked, for the umpteenth time, the box for sheer, enviable durability.

Despite the so clearly evident high humidity at the venue, he had a full 80-minute shift (something he traditionally relishes at all levels) and seemed to only get hungrier the longer the game went on, making at least two spirited, long-range defensive track-backs in the final quarter when certain colleagues might have been becoming a little more leaden.

It was a performance that would only, frankly, have deepened Erasmus’s already obvious faith in the full-blooded player; there is every reason to assume “Sous” will be wearing five again for the Boks’ massive RWC opener against the title-holding All Blacks at Yokohama in just under a fortnight.

Since he took over in 2018, the mastermind has almost always included Mostert in his starting XV for matches that have mattered most, if you like.

There have been 19 Tests so far in Erasmus’s tenure (14 last year, five in 2019) and the lean, Brits High School and Tuks-educated player has begun 14 of them – tending to only miss experimental-geared ones like the low-value tussle against Wales in Washington DC, or a couple this season where the coach has shielded the overwhelming majority of his core staff (Australia in Johannesburg, Argentina in Pretoria).

In marked contrast, Mostert was much more economically used as a starting presence during the two-year, largely uncelebrated Allister Coetzee regime: of his 18 Tests in that spell, 11 were as a match-day reserve.

In “Toetie’s” defence, at least he began to recognise the lock’s international potential, and he was also able to field a fully fit, firing De Jager during most of his time in charge.

Right now, though, a more meaningful look-in for either De Jager or Snyman seems unlikely in the short term, unless injury intervenes.

Oh, and remember: the machine that is Mostert isn’t terribly good at getting crocked …

*Follow our chief writer on Twitter: @RobHouwing