How Barcelona fans must wish they could go back in time.

They would probably choose to go back to 2008 - the start of the Pep Guardiola era at the Camp Nou.

An era that would see them win two Champions Leagues and three La Liga titles in four seasons.

During that time, they were arguably the greatest side football has ever seen.

With Guardiola in charge, Xavi and Andres Iniesta in midfield and Lionel Messi running riot, they were simply unstoppable.

It’s a far cry from where Barcelona find themselves now.

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Almost all of their stars have left and they’re currently sixth in the league and out of the Champions League.

You can’t blame Barca fans for feeling a little bit emotional when they stumble across videos of the good old days then.

And we’ve stumbled across one video that will pull on their heartstrings.

It features the Barcelona squad playing a futsal match against each other back in 2012. One side is managed by Guardiola at the end of his reign, while the late Tito Vilanova, who took over from Pep, managed the other side.

Pep’s side featured the likes of Jordi Masip, Sergio Busquets, Adriano, Andres Iniesta and Cristian Tello.

Meanwhile, Tito’s side included Pinto, Martín Montoya, Gerard Pique, Xavi and Pedro.

Goalkeeper Victor Valdes played something of a free role for both sides as he taped ‘Messi’ on the back of his shirt.

What followed was an incredibly entertaining game of football that finished 8-8. It’s actually been viewed a crazy 19 million times on YouTube.

VIDEO: Barcelona vs Barcelona at Futsal

Check it out:

Check out some of the reaction in the comments section on YouTube.

"So much positive energy in the arena. This video made me smile," one wrote.

Another added: "I am so emotional watching this game... This is the Barca we all loved. Not the lifeless Barcelona team we currently have! Valdes taping Messi on his back tho!"

"Best thing I've watched in a long time. So many things to talk about, it so much fun seeing all these players happy at Barcelona. I want Barcelona to be happy again. Pique and Valdez were actually really good. Messi was wearing Valdez skin. RIP Tito," a third commented.

A fourth wrote: "As a barca fan, I was just smiling all along."

I had a smile on my face throughout the video, now that it has ended, it's tears," another Barcelona supporter said.

Beautiful.

You really can’t blame Barca fans for feeling a bit nostalgic after that.