A third defeat against the Springboks in Cape Town next Saturday, with autumn Tests against the Springboks and New Zealand to come at Twickenham, would see Jones's position come under fierce scrutiny.
It would also leave the Rugby Football Union, currently in the middle of a cost-cutting exercise that will lead to 75 redundancies, with the difficult decision of either backing Jones a year out from the World Cup with the hope that there is still time to turn the side's fortunes around or make a change in the same year that they extended his contract to 2021.
In contrast the Springboks look a side reborn under new head coach Rassie Eramus. The appointment of the first black player, Siya Kolisi, to captain the Springboks in their 127-year history in the first Test victory at Ellis Park was described by one senior South Africa figure as the most momentous day since they came out of isolation in 1992.
Yesterday, Eramus's side backed up that statement with another firecracker of a display, full of ferocious intent, power and great passion to mark Tendai Mtawarira's 100th Springbok cap.
By the end England looked a distant second in the contest, despite once again, as they had done at Ellis Park, delivering a highly-promising start that yielded tries for Mike Brown and Jonny May after just 13 minutes. Remarkably they would not score again.
Instead the narrative once again followed a depressingly similar twist for England's supporters as it had in Johannesburg. From a position of strength, England's game management, numerous handling errors, and, most strikingly their discipline, let the Springboks back into the game all too easily and with it any hopes of keeping the series alive.
England's profligacy ignited such a ferocious response by the Springboks that by half-time, just as they had done in Ellis Park, had taken the lead and control of the game by half-time with a try by the totemic No 8 Duane Vermeulen and two penalties by Handre Pollard, the second a monster effort from 58-metres,
By then Billy Vunipola, who had been at the centre of England's high-tempo start, had been forced out of the action with a leg injury, and there would be no way back.
Apart from a dropped ball over the line by Brad Shields on his first start for England, they didn't come close to scoring again in the second half and it was only their rearguard defence that prevented South Africa from adding more to their total than a penalty try and a third penalty kick by Pollard.
The Springboks on home soil are a different beast, and you have to be in the stadium to get a true sense of the intensity they bring to their game when the home support find their voice. It is as compelling as it is fearsome and England ultimately found the challenge overwhelming.
And in Faf De Klerk, the Sale Sharks scrum-half, the Springboks had their perfect conductor, backing up his livewire display at Ellis Park with a breathtakingly fast game. His tempo at the base of the breakdown was critical in giving his big forwards the front-foot possession to hammer England's defensive line while the Damian de Allende also gave South Africa a productive midfield target.
Vermeulen, flanker Pieter-Steph du Toit and hooker Bongi Mbonambi gave the Springboks the edge up front with their hard carrying, an appropriately it was a 30-metre dash by Mtawarira that created the momentum for Vermeulen's try.
England's indiscipline and the inability to cope with the intensity and power of the Springboks revival saw the contest at times boil over into brawls during a fractious first half, and Maro Itoje and Mako Vunipola both came close to a yellow cards.
Their lack of structure was a marked contrast to the ease at which they had been able to carve open the Springbok defence in the first quarter, showing no ill effects of being woken up by a fire alarm going off at their Bloemfontein hotel at 6am on Saturday morning.
First Billy Vunipola forced the Springbok defence onto the back foot with a strong carry and after swift passing by Young and Farrell, May came off his wing to create the overlap on the left and he drew Willie Le Roux to put Brown over for his second try in as many matches.
South Africa's indifferent start continued when a penalty for obstruction allowed Farrell to set up an attacking line-out and from it England were able to strike from first phase, with George Ford looping around Farrell and a clever flick by Brown to Elliot Daly this time putting May away who finished strongly in the right-hand corner.
Yet having surrendered the lead and momentum by half-time, there would be no way back. The yellow card for Nathan Hughes, on for Vunipola, was indicative of England's disciplinary problems that have plagued them all season.
A powerhouse scrum by the Springboks culminated in a penalty try and such was their superiority in the closing stages they should really have scored more than Pollard's final penalty. A tough, tough night for England and even tougher times lie ahead.
