Manchester United's players did their best in testing conditions. They had completed a training session in the 38°C furnace of Washington's FedEx Field and were satisfying demands for autographs from 6,000 enthusiastic fans around the pitch, which normally stages the Washington Redskins' NFL games.
United's players could have been forgiven for giving up and returning to the air-conditioned sanctuary of the dressing room or team bus.
They had been on the road for almost three weeks as part of a five-game tour of Boston, Seattle, Chicago, New Jersey and now the American capital.
Team hotels had been besieged by fans as United's profile in the world's biggest consumer market continued to grow, something the Old Trafford club wilfully embrace.
Less than half of United's travelling party consisted of football-related staff: players, coaches and physios. The English Premier League champions, who were paid a reported £3 million (Dh18.1m) to play the games, took marketers, a media team and commercial staff, while club legends such as The National columnist Andrew Cole, Bryan Robson and Gary Neville were on hand to meet and greet sponsors and throw ceremonial first pitches at major league baseball games.
The fans delighted as big names such as Ryan Giggs, Nemanja Vidic and Wayne Rooney signed autographs in the Washington heat.
Despite the hysteria, several United players were distracted from the thrusting demands for their signatures when they heard a roar from the crowd.
They looked across to see players from Barcelona arriving for a training session to follow the United one.
United made the biggest noise of the European teams, such as Real Madrid, Juventus and Manchester City, touring the lucrative US market, but Barca are the best team on the planet and they have no shortage of US converts either.
Sixty two days after being outclassed by the Catalans for the second time in three years in the Champions League final, the United players could be forgiven for thinking "Oh no, not them again".
Sir Alex Ferguson will not engage such negative thoughts about Barca. Following defeat at Wembley Stadium on May 26, the United manager spoke of relishing a challenge.
He has faced many since taking over at Old Trafford almost a quarter of a century ago and, with the new season starting with this Sunday's Community Shield against Manchester City, Ferguson faces several new ones.
He not only has to maintain the domestic success that saw United win a record 19th title last term by seeing off rivals Chelsea, Arsenal, City and Liverpool, but to somehow counter Barca's European hegemony. Demands are high on the manager who turns 70 on December 31.
With players such as Barcelona's Gerrard Pique, Xavi, Carles Puyol and United's Rio Ferdinand not leaving the bench, neither side was at full strength when they met in a glamorous friendly game the following evening in front of a staggering 80,817 sell out crowd.
Barca were also without Lionel Messi, Daniel Alves and their new signing Alexis Sanchez, who do not report back for training until next Tuesday following their Copa America exertions.
They will return just five days before Barca take on Real Madrid in the first leg of the Spanish Super Cup.
Following the summer retirements of Edwin van der Sar and Paul Scholes - who has his testimonial game against the New York Cosmos this Friday - United's starting XI in Washington had an average age five years younger than that which started at Wembley.
Emerging youngsters, such as the striker Daniel Welbeck and the attacking midfielder Tom Cleverley, used their valuable minutes to impress, though it was Nani, the winger, who was the game's outstanding performer.
The Portuguese player, who lost his place in the United line-up towards the end of last season, combined with Welbeck to put United ahead after 14 minutes.
United held the lead until Barca's Thiago Alcantara showed why Pep Guardiola was so keen for him to commit to a five-year contract last month with a delightful second half equaliser.
Thiago has been Barca's best player in pre-season, with spectacular goals becoming his hallmark. The 20 year old's progress shows why many at Camp Nou are relaxed about whether Arsenal's Cesc Fabregas returns to Catalonia in a transfer saga which has stretched for two summers.
United counted on a player at the opposite end of the experience scale for the winning goal against the Catalans 14 minutes from time. Cleverley, 21, who has spent the last three seasons on loan and hopes for this to be his breakthrough season at Old Trafford, set Michael Owen free.
The veteran striker, 31, chipped low past Victor Valdes.
Defeats are rare for Barca, but this was their fourth game in a week and they were playing with two midfielders, Jonathan dos Santos and Sergio Busquets, in defence. They will play two more games in Miami and Dallas before returning to Spain next Monday to prepare for the Real clashes.
"We're happy winning the match against Barcelona," Ferguson said. "Both teams made a lot of changes so it's difficult to gauge exactly the importance of the result.
"But the expectation is for us to win all games and we're delighted to go into the season with a winning frame of mind."
Publicly, Ferguson maintains that he is content with his squad and he has been able to successfully bed in new signings Ashley Young, David de Gea and Phil Jones.
"We've integrated the new players well - they've done well settling in with players they don't really know," he said.
"I'm sure we're fit, I'm sure we've got a good squad and I've got some good young players coming through.
"These are all pluses - we have a squad able to deal with the demands of the English and European game. Now we move on to matters back home and hopefully we keep our form."
Speculation that further additions would be added continued throughout the tour and fans hoped that the frequent training ground conversations between Ferguson and David Gill, the chief executive, would be about the imminent arrival of Wesley Sneijder from Inter Milan.
United have made an offer for Sneijder, 27, but despite the Dutchman being amenable to a move to Old Trafford, they are unwilling to shatter the club's pay structure.
The reluctance is understandable, for not only would United's other stars demand parity in the next round of contract negotiations, but Sneijder would have a diminishing resale value given his advancing years.
In the US, United accumulated four consecutive wins against top-level American opponents, including an MLS All-Stars side counting Thierry Henry and David Beckham in their starting XI.
United triumphed 4-0, making it 18 goals scored and two conceded across four games - not that pre-season results count for much. But they will be hoping for more of the same against City in what will be one of the most keenly contested Community Shield games for years.