Felix Zwayer, one of Europe's top referees, pulled up with cramp towards the end of the USA's 2-0 win over Australia in their World Cup match at Lumen Field in Seattle.
The German official, 45, was struggling in the intense heat, which reached 26 degrees with 45% humidity. Despite the conditions, Zwayer had been keeping up with the pace of the match, brandishing a flurry of yellow cards at the end of what was a dominant victory for the USA.
As Zwayer fell to the turf, he required help from both the USA's Folarin Balogun and Australia's Aiden O'Neill, who stretched out his left leg. With just a couple of minutes of stoppage time remaining, Zwayer also required an energy gel, which was rushed onto the pitch by fourth official Katia Garcia.
Zwayer was able to get to his feet and see out the rest of the match, with the USA beating Australia 2-0 to reach the knockout stages.
It's not unusual to see players suffer cramp towards the end of matches taking place in hot conditions, while referees have to cover a lot of ground to keep up with play. As one of Europe's top referees, Zwayer has taken charge of high-profile matches, including the Euro 2024 semi-final between England and the Netherlands.