In 2013, during the Barclays Asia Trophy, Sunderland manager Paolo Di Canio described the pitch as "a killer", while Manchester City centre-back Matija Nastasić is injured on the mudheap pitch, although Nastasić's injury was caused by a kick to the ankle according to City manager Manuel Pellegrini, who refused to blame the muddy pitch. Tottenham Hotspur manager André Villas-Boas was also critical of the pitch after Jan Vertonghen, a first-choice Spurs defender, incurred an ankle injury playing on the surface. "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 AA. Manchester United then cancelled their public training session at the stadium on Sunday amid concerns over the playing surface, did not want to further damage the playing surface or risk any injuries to their players, ahead of their exhibition match with Kitchee SC on 29 July.