The Premier League’s top teams swarmed to Asia chasing the region’s growing wealth and unquenchable thirst for English football, but they go home counting the fitness costs. At least two key players - Jan Vertonghen of Spurs and Matija Nastasic of Manchester City - suffered injuries during friendlies that could see them miss the start of the season, which kicks off in under three weeks. Manchester United’s Wayne Rooney was in Bangkok for less than 24 hours when he sustained a hamstring injury in training and was immediately sent back to Britain for rehabilitation. He is at least expected back before the start of the season and is pencilled in for a return on August 6. Whether the England star, 27, is still a United man when the season gets underway remains to be seen - he is the subject of a big-money bid from title rivals Chelsea. United, the Premier League champions, say they do not want to sell. Spurs manger Andre Villas-Boas was in open revolt after seeing Vertonghen, a first-choice defender, pick up an ankle injury playing on a surface in Hong Kong that his Sunderland counterpart Paolo Di Canio branded “a killer pitch”. “If I can be sincere, I would prefer not to play, but this is the reality that we have to face,” said the Portuguese on the eve of his side’s friendly against South China. After seeing his team hammer the hopelessly outclassed local side 6-0, Villas-Boas said that he was just relieved to get out without any more injuries. Hours later Manchester City manager Manuel Pellegrini found himself in the same boat when he lost first-pick centre-half Nastasic, also at Hong Kong Stadium, where days of heavy rain had the players slipping and sliding dangerously. The young Serbian’s injury was caused by a kick to the ankle, said Pellegrini, refusing to blame the muddy pitch. Nastasic appeared to be in considerable pain as he was stretchered from the field in front of a 40,000 sell-out crowd. Manchester United were the most ambitious, jet-setting on a whistlestop tour of Thailand, Australia, Japan and Hong Kong. They played five times in just 17 days. Their manager David Moyes said it was inevitable players would pick up minor injuries in such a tight schedule. “When you’ve been away for three weeks and played the games in quick succession and had to travel there’s always going to be slight niggles and strains which you want to protect,” he said. His Arsenal counterpart Arsene Wenger, whose side embarked on a two-week tour that took in Vietnam, Japan and Indonesia - where temperatures nudged above 32 degrees Celsius (90F) - also admitted four games in 13 days had taken its toll. “We are well advanced in our preparation,” Wenger said. “It depends now on how quickly we’ll recover from that trip because it was very difficult. It will take a few days to recover from that.” The England striker Jermain Defoe, who hit a hat-trick in the romp over South China, was another to admit that playing on the other side of the world in the fierce summer heat and humidity had been draining. “A lot of the boys have been really tired to be honest, as you can imagine with the time difference and training twice a day,” he said. “But it’s a long season and you need to get fit. It’s not a holiday, at the end of the day. We’ve had six or seven weeks to have our holidays and that, and now it’s time to work.” Liverpool were also in town, playing friendlies in Indonesia, Australia and Thailand that racked up a total of seven goals, but thankfully for manager Brendan Rodgers there were no significant injury worries.