With the 2018 World Cup now over, it's all about the upcoming club season in Europe and other leagues around the world are starting back up. But before the meaningful games arrive for the world's biggest clubs, there are plenty of preseason tests from monster stadiums in the United States to matches with glorious backgrounds in the Swiss mountains. But what matches do you need to keep an eye on? Here are five preseason matches to watch and why, keeping in mind that we are looking more at matches towards the end of the summer to give superstars more time to get back after the World Cup and vacation:

Bayern Munich vs. Manchester City, July 28 (7 p.m. ET, ESPN)

A fun match in the International Champions Cup that will be played in Miami, it's a battle between two teams looked at as Champions League contenders. Neither team has been particularly busy during the transfer market, but it still should see a boatload of talent on the field. We'll have to wait and see how many of the top players feature after the World Cup, but it will be a good chance to see Algerian star Riyad Mahrez with City. 

Manchester United vs. Real Madrid, July 31 (8 p.m. ET, ESPN2)

Always a huge matchup, one that has produced some classics in the past. Who would have thought Manchester United is entering this friendly as arguably the better squad? That's how big of a difference Cristiano Ronaldo's departure from Madrid is. Manchester United will likely feature new signings Fred and Diogo Dalot, while Real Madrid is sure to be busy in the transfer market ahead of this one. Keep an eye on United's new signings as they look to boost the quality this team has, especially on the ball, in an effort to make a leap in Europe and contend for the Premier League crown.

Arsenal vs. Chelsea, Aug. 1 (3 p.m., ESPN2)

Both teams are with new managers, as Unai Emery replaced Arsene Wenger at the Emirates and Maurizio Sarri took over for fellow Italian Antonio Conte. Arsenal has brought in about four new starters, headlined by dynamic, young Uruguayan midfielder Lucas Torreira. We'll see how this squad responds to Emery as coach, but he is at a job that has proven to be patient when it comes to the manager, so he should have some time to get this team back on track. As for Chelsea, rumors of Eden Hazard's departure could move this team from top-four contenders to possibly out of the top six if the Belgian star does indeed leave. 

MLS All-Stars vs. Juventus, Aug. 1 (7:30 p.m., ESPN)

A fantastic showcase for MLS against one of the hottest teams in the world. We've got the MLS All-Stars taking on mighty Juventus in Atlanta. Now, it was always going to be a sweet matchup against a team featuring guys like Paulo Dybala, but the match looked even better when Cristiano Ronaldo signed with Juventus earlier in the month. But Ronaldo won't be with Juve in the U.S. for the preseason, so it takes a little out of the matchup. Still, it's a good preseason test for the Italian giants against a team that will be determined to beat them, and it is also another chance for Massimo Alegri to figure out his goalkeeping situation with Gianluigi Buffon now at PSG.

Barcelona vs. Boca Juniors, Aug. 15 (12:30 p.m. ET, TV TBD) 

This will be a fun one, and it will be a showcase for what Barcelona has to offer this season in the Joan Gamper Trophy match, but it will also be a good look for European teams trying to poach some of the top talent from South America. Boca Juniors currently has a good amount of talent linked with Europe, with none bigger than Cristian Pavon. The dynamic winger is a teammate of Lionel Messi's on the Argentina national team, and boy do they gel well on the field. It will be a good look for Barcelona, in the event it decides to pursue the player, though the expectation is for him to stay through the Copa Libertadores campaign. As for Barca, we should see new signings Arthur and Clement Lenglet play as both look set to assume important roles with the team this upcoming season, with winning the Champions League being the goal.

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