FC Barcelona: 7 Teams That Could Beat Them in Europe and Why

Barcelona blazed through the Champions League last term on the way to its third title in the last five years.

Along the way, Leo Messi and company earned the title of "best team ever" from some quarters.

It's a new season, though, and Barcelona has to beat everyone again to win another title.

Will it happen?

Only time will tell. But we think the Catalans, like every team, are vulnerable.

That's not to say Pep Guardiola's side will definitely lose in Europe sometime this year. For all we know, they could beat everyone by five goals while pillaging the town like medieval warriors.

Or not.

Actually, we think somebody will get the job done this season against Barcelona. Here are seven potential candidates.

Real Madrid

Real Madrid is Barcelona's biggest rival.

Duh, you say? Well, in rivalries, anything can happen. Throw the form guides out the window. These two teams will always put on a show.

Beyond the rivalry angle, though, Real Madrid might be the second best team in Europe behind Barcelona. And Jose Mourinho's side has a legitimate shot at knocking Barca off its perch.

Why?

For starters, let's talk about Mourinho. "The Special One" has made a habit of winning throughout his often controversial career in management.

Perhaps his biggest triumph came two seasons ago when his Inter club claimed the Champions League trophy. Along the way they beat Barcelona over two legs in the semifinals.

At Real Madrid, Mourinho has arguably more talent at his disposal. Cristiano Ronaldo is one of the world's top players, while Mesut Özil is a rising star.

For all those reasons, Real Madrid poses the biggest threat to Barcelona's European hegemony this season.

Manchester United

Manchester United and manager Alex Ferguson know how to grind out results.

They've been doing it for decades, and this season might be the time they break through against Barcelona.

In Nemanja Vidic, United has perhaps the world's top defender. In Wayne Rooney, they have one of the world's most in-form strikers. In Ashley Young, they have an exciting, up-and-coming midfielder.

The trick will be getting all the parts performing at the same time.

Vidic must make a successful return from injury. Rooney must keep up his form. Young must prove himself as a top European player in the group stages.

If Manchester United can translate its early-season form in the Premier League to Europe, the Red Devils could definitely knock off Barcelona.

But they'll have to play a perfect match and keep it low-scoring.

Valencia

Valencia has the advantage (or is it a disadvantage) of playing in the same league as Barcelona.

That means they know better than just about anyone in the Champions League (apart from Real Madrid) how to beat Barca.

However, actually beating the champions will be harder in practice than in theory.

But Valencia has a chance. Roberto Soldado is a cool finisher who is doing as well as can be expected for someone trying to replace the departed David Villa.

Meanwhile, Pablo Piatti is a strong addition in the attack, Dani Parejo is a rising star and Unai Emery pulls the strings in midfield.

In addition, Valencia already tied Barca 2-2 in La Liga action.

First, though, they'll have to get through a tough Group E with Chelsea and Bayer Leverkusen.

AC Milan

Remember how AC Milan fought back against Barcelona on Matchday 1 of the Champions League earlier this season?

Remember how Milan had chances to win?

That's why they can beat Barca—because they've already shown it's possible.

The Rossoneri have the star power in attack to compete with Barcelona thanks to players like Zlatan Ibrahimovic, Alex Pato and Robinho.

Experienced midfielders like Alberto Aquilani, Gennaro Gattuso and Clarence Seedorf give Milan bite.

Massimiliano Allegri's task will be finding the right combination of experience and flair. Don't be surprised if he finds it.

Bayern Munich

Never count out German giants Bayern Munich, who are always well-organized and efficient.

Led by vastly experienced manager Jupp Heynckes, formerly of Real Madrid and Bayer Leverkusen, Bayern's plan this year is to build from the back and employ a more physical approach.

That should suit Bayern's personnel. Main man Bastian Schweinsteiger is a combative central midfielder, while the defense has plenty of grit and talent.

Throw in the mercurial talent of Arjen Robben and the exciting flair of youngster Thomas Müller, and you have a formidable team.

It's a team that could knock off Barca on a good day.

Chelsea

Chelsea is getting a fresh start under exciting young manager Andre Villas-Boas, who became the youngest UEFA Cup-winning manager last term with Porto.

The 33-year-old has an experienced but aging squad with a few upsides at his disposal.

Any discussion of Chelsea's form needs to start with Fernando Torres, who struggled for several months after his move from Liverpool, but is now starting to play well again. If he continues his strong form, Chelsea is a dangerous side.

The old guard of Frank Lampard, John Terry, Didier Drogba and Nicolas Anelka made a deep run a few years ago. They have the experience, but time is running out.

Napoli

Napoli is a bit of a dark horse this season in the Champions League.

The Italians drew a tough group with Bayern Munich, Manchester City and Villareal, but have the quality to go through.

And they have the quality to challenge Barca, too.

The Azzurri boast a great back line led by Paolo Cannavaro, the younger brother of Fabio, along with Hugo Campagnaro and Miguel Angel Britos. Playing a three-man back line against Barca might seem like suicide, but the extra man in the midfield could actually slow down the European champs.

Speaking of the midfield, Napoli boasts the considerable talents of Slovakian playmaker Marek Hamsik, one of the best in the game right now.