Oxygen tanks may even be provided at the side of the pitch for the friendly, as Brazil did when facing Bolivia in La Paz last year. At 7,400 feet above sea level, Mexico City is more than 4,000 feet lower than the Bolivian capital but there can still be issues with mild shortness of breath, increased fatigue and feelings of nausea.
McLeish, who yesterday named his squad for the end of season tour, recognises that his players cannot avoid the effects of a city that also has problems with smog.
In order to limit exposure to the higher altitude the squad will not travel from Peru – where they play on Tuesday 29 May – until the afternoon before the game at the Azteca Stadium on Saturday 2 June.
McLeish said: “If players need more oxygen or whatever then of course there are going to be facilities there.
“The performance guys have done their homework and it looks like we can’t be in Mexico City two or three days before because you don’t acclimatise in that time. It’s more a case of arriving the day before, playing the game.
“According to what Graeme [Jones, SFA performance chief] has been told by players with experience of playing at altitude in the MLS and other sports in Mexico City, the best preparation is just to arrive the day before.
“The altitude can make you lethargic and feel one paced, that kind of thing. A lot of the South Americans, when they go to Bolivia and the likes, seem to suffer. We’re doing everything we can preparation wise. Mexico looks as if it could be the harder fixture of the two in terms of acclimatisation.
McLeish’s maintained he has not named a “weak” squad, despite making “concessions” in omitting five Celtic players – Kieran Tierney, Leigh Griffiths, James Forrest, Callum McGregor and Craig Gordon – after two years when the club has played “a lot of football”.
McLeish is also without Andrew Robertson, who will be preparing for Liverpool’s Champions League final against Real Madrid on 26 May, when Scotland fly out next Friday. The 24-man pool includes three new call-ups in John Souttar, Lewis Stevenson and Lewis Morgan and seven uncapped players.
McLeish said: “Do I think these guys can cope instead of the guys missing? Absolutely, 100 per cent. I feel confident about the players we’re taking.
“They’re a warm-up act for two World Cup teams. It looks as if they are going to have two big parties but we want to spoil them. It won’t be easy with the altitude in Mexico and the heat in Peru. We will essentially need two teams and can’t play a high pressing game.
“It was all done before I came in so we’ve got to embrace this. We want to get results but we know the bigger picture are the [Uefa Nations League] games in September.”