Manchester United and Real Madrid have been involved in a heated row over their summer tour arrangements in Los Angeles. Both clubs picked the city as their pre-season base, which has led to a series of arguments over everything from hotels to training pitches as they battle for supremacy.

Relations between United and Real have even soured to the point that officials at Relevent Sports, organisers of the International Champions Cup (ICC), have been forced to intervene in an effort to placate both parties.

Sources have admitted the situation has been a “nightmare” to deal with and is likely to ensure a tense meeting when the teams face each other in the ICC at the Levi’s Stadium in Santa Clara on July 23, in what will be United’s fourth game of their tour. They also face each other in the European Super Cup in Macedonia on August 8.

United and Real’s uneasy relation-ship dates back to the Spanish club’s courtship of Cristiano Ronaldo. Sir Alex Ferguson, the former United manager, famously declared that he would “not sell that mob a virus” when asked about the possibility of Ronaldo joining Real, only later to sell the Portugal forward for a then world-record £80 million in 2009.