The Red Devils may be the current holders of both the Europa League and the English Football League Cup, but those are relatively minor trophies compared to what the record 20-time champions of England are used to winning, and José Mourinho will be aiming for bigger things in the 2017/18 season.
This game with Barça will provide an ideal opportunity to see how well-prepared his side is for coping with that challenge.
Since taking over at Old Trafford last summer, the Portuguese coach has imprinted his ideas on the team while combining it with the typical style of British football – direct route one tactics coupled with an intense team ethic and tough but fair physicality.
There have been very few modifications with respect to last season’s squad, but these changes have been big ones. Belgian striker Romelu Lukaku arrives from Everton and should offer plenty of firepower up front, while Swedish defender Víctor Lindelöf has been signed from Benfica.
Andreas Pereira and Guillermo Varela have both returned from loan deals to Granada and Eintracht Frankfurt respectively.
There has been more movement outwards, with Wayne Rooney going back to his boyhood club Everton and Swede Zlatan Ibrahimovic being released after his contract came to an end. Other changes include Belgian Adnan Januzaj being sold to Real Sociedad.
Man United are much further into the preseason than Barça, having already played four games in the US. They started with back-to-back victories against MLS clubs, a 5-2 defeat of LA Galaxy and a 2-1 win against Real Salt Lake.
They followed that with a stateside version of their local derby, beating Man City 2-0 with goals from Lukaku and Rashford, and on Sunday in Los Angeles, they held Real Madrid 1-1 (and won 2-1 on penalties) in a dress rehearsal of the UEFA Super Cup on August 8 in Skopje, Macedonia.
The game with FC Barcelona kicks off this Thursday 27 July at 7.35pm EST (Friday 1.35am CET) at the FedEx Field, Washington DC.
United have two more friendlies, against Vålerenga of Norway and Sampdoria of Italy, before their season officially gets under way.