England will have to overcome an in-form team, as well as changeable weather patterns, and the effects of playing at altitude if they want to reach the quarter-finals of the World Cup.
Thomas Tuchel’s side take on tournament co-hosts Mexico on Sunday night at the famous Azteca Stadium, located more than 7,000ft above sea level.
It is a formidable fortress for the home side, at which they have a record of 70 wins from 89 games, with 17 draws and only two defeats.
Playing at altitude makes the air thinner, enabling players to absorb less oxygen into the bloodstream.
“Maximum aerobic capacity at this kind of altitude usually drops around 10%, and that has a knock-on to performance,” Dr Barney Wainwright, senior research fellow at Leeds Beckett University, told the BBC.
“There will usually be a 15-20% increase in fatigue. For the distance it’s possible to cover, we would expect that to drop by 5-10%.
“Players will produce lactate much more quickly, creating an acidity in the muscle which builds fatigue and slows them down.
“Maximum sprint speeds won’t be affected, but players will need to wait a bit longer to recover from each one and go again.
“We need oxygen in the brain for perception and decision-making, so particularly in the moments of the game where players are working really hard, that could impact key decisions.”
Altitude can also affect sleep, as can hundreds of noisy Mexicans with fireworks, as seen before the round of 32 game against Ecuador.
England were hoping to keep the whereabouts of their hotel secret but the location was quickly leaked, prompting fears the Three Lions squad could be targeted.
The weather is another element that England cannot control, although that is the same for both sides.
Thunderstorms are expected in the area on Sunday night, prompting reports FIFA were going to bring kick-off forward. The game was eventually confirmed for 6pm local time, although there is a strong chance it could be delayed.
The additional issues around the game would feel less of a problem if England were in good form, but they have looked disjointed so far.
Bar a 45-minute mauling of Croatia in their first game, Tuchel has failed to get a good performance from the team in a goalless draw with Ghana and patchy wins over Panama and DR Congo.
Mexico, on the other hand, have been flying.
Javier Aguirre’s side have won all four games and are yet to concede.
Striker Raul Jimenez said: “We’re fully focused and united. That sense of togetherness and family spirit is spurring us on to great things. We’ve still got another match to play here in Mexico. And we’re fully aware of what’s at stake.
“We’re going to give it our absolute all and keep giving the fans something to shout about. We’ve got a really strong side, and there’s been a real sense of togetherness since Vasco [Aguirre] took charge. The sky’s the limit.”
Team news for Mexico v England
Mexico have no new concerns and Aguirre could name an unchanged team.
England midfielder Declan Rice is expected to be fit despite an ongoing hamstring problem. Djed Spence is likely to continue at right-back in the absence of Reece James. Tuchel may recall wingers Bukayo Saka and Anthony Gordon.
