Nations Championship: Do England’s rugby players face greater challenge at altitude in South Africa?

One word has dominated the build-up to England's World Cup last-16 clash against Mexico at the Azteca Stadium: altitude.

But there is an argument that the challenge facing Thomas Tuchel's side isn't even the greatest an England team will tackle this weekend.

The altitude - all 2,200m (7,220ft) of it - and atmosphere at the iconic Estadio Azteca arguably outweigh the challenge that awaits England on the field.

England must overcome tournament co-hosts Mexico, a side ranked six places below them in the FIFA World Rankings, to reach the quarter-finals.

No knockout match at a World Cup is easy, and when you combine all the factors - altitude, atmosphere and opposition - England's progress is far from certain, especially given their performances leading up to this stage.

But try contrasting that with what awaits England's rugby players several thousand feet above sea level in Johannesburg.

The standout fixture from the opening round of the inaugural Nations Championship sees Steve Borthwick's side travel to Ellis Park, the fortress of South African rugby, for an acid test against the reigning, back-to-back World Cup-winning Springboks.

Ellis Park, a venue where England's sole victory came in 1972, may sit at a lower elevation than the Estadio Azteca, a more modest 1,753m (5,751ft) above sea level, but it adds another dimension to what is currently the greatest challenge in world rugby.