The Red Devils have clocked up 22,000 miles so far on their world tour after having played four matches—beating Amazulu 1-0 in Durban, South Africa before drawing 1-1 with Ajax Cape Town in the country's legislative capital.
That preceded a 1-0 win in China over Shanghai Shenghua, before a trip to Norway saw United's youngsters go home and the Euro 2012 stars come in, with the senior players simply playing to gain match fitness in a 0-0 draw with Valerenga.
Barca, on the other hand, have had a shorter, if more spectacular preseason campaign, beating Hamburg SV 2-1 in Germany before thrashing Raja Casablanca 8-0 in Morocco, all preceded by a 4-1 penalty shoot-out win over Paris Saint-Germain following a 2-2 draw.
United will aim for a second successive win over Barca, with the Premier League giants having beaten their La Liga counterparts in a preseason friendly last season.
Here is a complete preview of the game in Gothenburg.
Manchester United and Barcelona are both set to name near full-strength starting line-ups as they look to get their main players up to full match fitness and back in form.
Patrice Evra will be back in the mix for United after missing the Valerenga match as his wife gave birth to their second child, while Antonio Valencia is set to continue at right-back with Rafael on Olympic duty.
Shinji Kagawa looks set to continue on the bench as manager Sir Alex Ferguson tries to get both Wayne Rooney and Danny Welbeck back up to full match fitness following their extended break after Euro 2012.
United's full-match squad for the game can be seen here.
As for Barcelona, they're also set to name a strong line-up with their Euro 2012 stars returning to action, with Cesc Fabregas, Xavi, Andres Iniesta and Gerard Pique in line for their first starts of pre-season.
Lionel Messi, Alexis Sanchez, Carles Puyol and Dani Alves will also feature, having started in Barca's last outing against PSG, while youngsters Carles Planas, Rafinha Alcantara and Sergi Roberto should all get a chance to shine.
United: David De Gea, Antonio Valencia, Rio Ferdinand, Nemanja Vidic, Patrice Evra, Nani, Paul Scholes, Michael Carrick, Ashley Young, Danny Welbeck, Wayne Rooney
Barca: Victor Valdes, Dani Alves, Gerard Pique, Carles Puyol, Carles Planas, Sergio Busquets, Xavi, Andres Iniesta, Alexis Sanchez, Lionel Messi, Rafinha Alcantara
Here are the key match-ups to watch:
Nani vs. Carles Planas
With Jordi Alba away on Olympic duty and Eric Abidal still recovering from his liver transplant, Carles Planas has been given a golden opportunity in preseason by manager Tito Vilanova to prove his worth.
Against United on Wednesday, he'll have his toughest test yet, tasked with keeping Nani quiet.
The Portuguese star, like Planas, will have to prove his worth in preseason, with his inconsistent form and his team's interest in winger Lucas Moura putting his place in the side in doubt.
With the game important to both players, a big battle on the flank is to be expected.
Nemanja Vidic vs. Lionel Messi
Nemanja Vidic's return from injury continues with a matchup against the world's best player, Lionel Messi.
After coming through 60 minutes versus Valerenga in Norway, Vidic will now face a bigger test of his fitness as he aims to control the movement and link-up play of Messi.
It'll be a good battle for Vidic, and win or lose, it will give him that experience once again of playing against forwards at the top end of the game.
Manchester United's form going into their glamour friendly is decent, but it could definitely be better.
Defensively the team are sound, with only one goal conceded throughout their whole tour—and that goal was an understandable lack of concentration.
However, in attack it's a different story for the Red Devils. In all four preseason matches, they've created some good link-up play in and around the penalty area, but possess a major lack of conviction in their finishing.
Javier Hernandez squandered a lot of good chances in the African leg of the tour, while against Valerenga, Danny Welbeck wasted a number of great opportunities.
Ahead of the new Premier League season, United will need to find their attacking rhythm asap.
Unlike United, Barcelona have made some of their good play count, with their tiki-taka football producing 12 goals in three games.
However, eight of those were against a very weak Moroccan team, with two goals apiece against PSG and Hamburg.
And in the games against their European counterparts, in typical Barca style, the Catalan giants scored only half the number of goals they should have.
In defence, the Camp Nou outfit have been weaker than United, with a lack of concentration being their main weakness.
It shouldn't be too much of a problem against the Premier League team with Rooney and Welbeck still trying to find decent form, but if they want to topple Real Madrid, it's something they'll need to improve upon.
After making his return against Valerenga, Manchester United centre-back Nemanja Vidic is relishing a test against Barcelona. He said (h/t SkySports):
It [Barcelona] will be a tough game, but obviously it will be a good test for us. We need those games before the league starts. We have to know it's a friendly game and it doesn't count for the trophies and points.
Last year we beat Barcelona in a friendly game and lost in a final.
Meanwhile, Barcelona midfielder Andres Iniesta also believes the glamour tie will be a useful exercise, telling Barca's official website about the United game:
It's always hard, because it's the start of the season, but tougher opponents oblige you to put more into your game. Indirectly, it's better, because you have to get into shape quicker.
Players on both sides seem to be looking forward to the match, with Wayne Rooney being another. He told United's official website:
It's great to play in big games and Barcelona is one of them. It's all part of our preparation and we need to make sure we do the right things. We want to enjoy the game and get our fitness ready for the first game of the season.
Manchester United have looked great defensively all preseason, so it's unlikely they'll get thrashed by Barcelona.
However, they've been off the pace up-front, with their glut of wasted chances each game frustrating the fans.
Barca have also lacked conviction, but not to the same extent as United—though they have looked weaker than United in defence.
It'll be a tight game in Gothenburg with only a small number of goals, but given their form in preseason, Barca are favourites to edge it.
FC Barcelona 2-1 Manchester United