Pre-season tours have grown significantly in importance over the past decade as teams promote their brand.
Pre-season tours have grown significantly in importance over the past decade as teams promote their brand visibility while simultaneously striving to ensure players are ready to hit the ground running.
Asia, Australia and the United States are popular destinations for the top clubs, but there is more to these trips than simply pitching up and kicking a ball.
AC Milan and Borussia Dortmund kick off the International Champions Cup (ICC) in Guangzhou, China, on July 18, the first of 19 matches in a pre-season tournament featuring several of Europe's top clubs spread across three countries.
Bundesliga giants Bayern Munich then meet Arsenal in Shanghai before the Gunners take on Premier League champions Chelsea in Beijing.
"What I really stress whenever somebody comes out here is that the game is probably actually the least important part. It's really just 90 minutes," Tom Elsden, senior client manager with Shanghai-based Mailman Group, told AFP.
"You can't expect to come out here on a China tour or do one deal and you've made it. It's a continuous commitment to this market."
"You need to come out every year or other year to continue that connection with fans, relationships with sponsors and grassroots initiatives. It's a long-term play."
Elsden, whose company handles the China digital marketing presence for a range of internationally known players, clubs and leagues, adds: "In China, this is still the first generation of real sports fans. So teams can come out here for the next five, 10, 15 years and pull in a fan that has no natural allegiance."
Chelsea, Bayern and Inter Milan will also visit Singapore, but the bulk of the fixtures take place Stateside where Jose Mourinho's United play Pep Guardiola's City on July 20th in Houston, with European champions Real meeting arch rivals Barcelona in Miami on July 29 -- the first Clasico held outside Spain since 1982 in Venezuela.
Charlie Stillitano, chairman of Relevent Sports which oversees the ICC, believes the appeal of the US is its "perfect marriage of commercialism and football".
"(Clubs) have an opportunity to have training facilities which are second to none," says Stillitano. "(Zinedine) Zidane came last year (with Real), they didn't do anything except train for 10 days, then they play very competitive matches.
"It was always thought that pre-seasons should be playing against easy teams, don't stress the players, they will only come to America for really what they said was marketing, but they weren't really doing much, except just coming."
"Now everything has changed. Now the players are serious, the commercial departments are serious."
Stillitano credits Mourinho for changing the way clubs approach their pre-season plans.
"The guy who really led the way was Jose Mourinho in 2004. Alex Ferguson said later in his book that he learned a lot from Jose, because Jose won the Premier League two years in a row and Jose attributed the two titles in a row to playing big teams in pre-seasons and being ready," he explained.
But Stillitano notes the marked difference between tours to the US and Asia.
"The idea of a long pre-season doesn't really exist in China or Singapore," he says. "It's much more commercially driven, they come in, try to play games in a short amount of time, they do their preparation first at home and then leave."
After the Manchester derby, United will play Real in Santa Clara -- a fixture that drew a record US crowd of 109,318 at Michigan Stadium in 2014 -- in a dress rehearsal for next month's European Super Cup, before meeting Barca, while City play Real in Los Angeles and round out their tour against Tottenham Hotspur.
"The US, which we're visiting this year, and China, which we toured last summer, are two of the biggest and fastest growing football markets in the world," says Tom Glick, chief commercial officer at City Football Group.
"There are few better ways to enhance awareness and exposure of our club in particular markets than having our players on the ground, training, playing and meeting fans."