Cape Town - The Springboks had some issues surrounding the low-miles-in-legs sharpness at the outset of their then-captain Jean de Villiers, after long-term injury, at the last World Cup in 2015 ... is history possibly repeating itself?

Siya Kolisi was - a little unconventionally, given his leadership status - the first Bok to be substituted by coach Rassie Erasmus in the disappointing, though not disastrous, 23-13 defeat to the All Blacks in the World Cup Pool B opener at Yokohama on Saturday.

He was replaced by veteran Francois Louw at open-side flank in the 51st minute of the contest, before a more pronounced summoning of players from the splinters a few minutes later.

There had been no indication, at the time of writing, that Kolisi suffered any notable mishap leading to the change, and he had certainly been one of the quieter Bok forwards in a generally industrious pack (Bok frailties tended to lie more conspicuously in several berths behind the scrum).

Fellow loose forward Duane Vermeulen, playing his 50th Test, took over the leadership.

It is pretty clear that the frontline skipper has not yet regained his most explosive form, a phenomenon that had also been evident in the last Test preceding RWC 2019, against host nation Japan a fortnight ago when South Africa won 41-7.

Kolisi was subdued, by his standards, throughout the first half of that game, although he was starting to gather a head of steam before being called off after a 66-minute shift.

Ahead of that, he had only played 52 minutes in his first international exposure of the season - following a knee injury picked up during Super Rugby for the Stormers in May - against Argentina at Loftus, when he led an experimental Bok combo a week after they had clinched the Rugby Championship against the Pumas away.

Many players require some time to regain maximum confidence, strength and speed after knee issues, and Kolisi may still be feeling his way back to his best.

For that reason, it seems to makes sense for Erasmus to buck, in Kolisi’s case, the expected trend of resting the vast nucleus his “A-team” for game two of the World Cup against neighbours and global No 23-ranked Namibia at the City of Toyota Stadium next Saturday (11:45 SA time).

If Kolisi is in need of more of a gallop, it shapes up as an ideal, presumably not too demanding opportunity for the flanker to get it, aiding his quest to find optimal form for the still very likely knockout phase for the Boks.

Even a Bok “dirt-tracker” side should comfortably down the Namibians, who have lost both prior Tests to their more heavyweight foes by huge margins: 105-13 at Newlands in 2007, and 87-0 at the 2011 World Cup (North Harbour).

The Boks then have a six-day turnaround to their second-last group game, against Italy, which is also expected to be the last time they field their premier troops before the knockouts, on the assumption they still go that far. The final pool game is against another minnow outfit, Canada.

In fairness to Kolisi, he wasn’t the worst-performing Springbok against the All Blacks: there were notably poor outings in the backline, for example, from the likes of Willie le Roux, Makazole Mapimpi, Faf de Klerk and - a rare event in 2019 - Handre Pollard.

But his is almost certainly more of a “lack of game-time” problem at this point, so a chance to stretch the legs in a fairly likely try-fest against Namibia could do wonders for him.

The popular 28-year-old gradually working his way back to his best through reasonably prolific duty in the remainder of Pool B combat, before the quarter-finals, would also help stave off any possibility - albeit highly unlikely - of an embarrassing “Wynand Claassen” type of conundrum cropping up.

On the broadly stormy, demo-laden 1981 Bok tour of New Zealand, the Bok brains trust left out designated tour captain Claassen for the first of three Tests - SA lost 14-9 at Christchurch - before restoring him for the next two in a series surrendered 2-1.

*Follow our chief writer on Twitter: @RobHouwing