Wales boss Chris Coleman has blamed hot and humid conditions for his side's 2-0 defeat to Mexico.
A brace from Aldo De Nigris condemned the 41-year-old to a loss in his first game in charge of his country at the MetLife Stadium in New Jersey.
Coleman said that it was a tough game for his players, who are shattered after a long season.
"It was a tough game for us," Coleman told Sky Sports News. "Mexico are a super team, they play with imagination and move the ball well. They have quality in most areas.
"We suffered with the weather. Our boys have had three weeks rest since the end of the season, we have had four training sessions, just four hours of preparation for this game.
"We knew conditions would be hot and humid and we are not used to that."
The former Fulham manager amassed 32 caps for Wales during his playing career.