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It was an unthinkable scenario for many seasons: that Lionel Messi might depart Barcelona, and the Camp Nou club would have to find the replacement for him.

In the eyes of some, a direct replacement isn't a possibility; the multiple Ballon d'Or winner has redefined what it means to be the world's best at times, and he has carried Barcelona to successes on the back of his brilliance.

But now, with just a few months left on his current contract, the need to replace the No. 10 might be alarmingly sooner than expected. PA Sport (h/t ESPN FC) reported club president Josep Bartomeu told 8tv (h/t Barcelona's official website) that the deal has been signed, by Messi's father and representative, but since there is no official confirmation of his stay being extended, fans are bound to get more anxious as time goes on.

Whether it's at the end of the season, in a few years or right at the end of his playing career, though, the question remains the same for the Catalan faithful: Just how do you replace one of the greatest of all time? We've spoken with five Barcelona fans to find out just who they think could be the one to fill Messi's shoes somewhere down the line.

La Masia revival

For many years, the talent coming through the academy system at La Masia to Barcelona's first team was incredible. Not just Messi, but other forwards including Pedro, Bojan Krkic and Gabri all made waves in the first team for varying lengths of time.

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Meanwhile, the midfield was stocked thanks to a set style of play, ingrained in youngsters from the moment they set foot through the club doors, and two of those—Andres Iniesta and Sergio Busquets—remain integral parts of the team. A few years down the line and the same discussions will be had over how exactly to replace Busquets, the greatest in his position for a decade.

But the production line failed.

The signs were there when some—Isaac Cuenca, Gerard Deulofeu, Cristian Tello—were given chances despite being well below the level of the first-teamers they were trying to displace. Since then it has been a similar story—see Sandro and Munir—with only Rafinha and Sergi Roberto battling through enough to play a regular role.

But perhaps that could change soon. The talent drain at the club has to be reversed for that to happen, but as Deulofeu, Denis Suarez and others have shown, there's always a route back to Barcelona even if players don't make the grade first time around.

Fan and social account @WeAreMessi believes a recent departure could be the one to turn back to in the future.

"If there was someone we could pick as a long-term successor to Messi, then we'd love to see Jordi Mboula fill those shoes.

"An 18-year-old former La Masia winger, known for his dribbling skills with terrific pace, can be a contender to take the big role in three-to-five years' time. He's already got the skills and proved himself, but the board, as usual, wasn't able to keep him.

"He is first-team material with AS Monaco and on the right path to making a huge name for himself like many other former players out there. Honestly, to predict who could probably be the face of Barca is a tough call and with so many 'next Messi' options who have faded, there aren't many options to pick from."

Mboula is yet to make a Ligue 1 appearance with Monaco after joining this summer, but he's again ripping up the UEFA Youth League, with four goals in as many games so far.

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There are others, still within the Barcelona system, who could yet prove equally exciting as a potential successor.

The @YoungCules social account runs the rule over La Masia teams and Jeffrey from the site gave his own views on who those graduates might be.

"It is of course very unlikely, or impossible even, that someone can actually replace Messi like for like.

"There is still a lot of talent in La Masia, but it is very early to say if they can make it, especially in the forward department. Barca B's Abel Ruiz has been tearing it up for Spain U17 and he's a great talent for that striker spot.

"In that same side, we have Sergio Gomez (Juvenil A/U19) who is a good talent.

"But as I said earlier, there's so much development still to do for these La Masia players, and there is more talent further down the ranks as well.

"In terms of purchases I'm even more clueless! Kylian Mbappe seems like a world-class purchase for that left forward position, but PSG has that locked down already."

Possible, but not probable, then, that Barcelona could replace their own with their own.

From within

Not coming from the academy doesn't mean Barcelona don't already have the star they need, however.

This is a club filled with talent in attack, and with plenty of variations when everybody is fit and available. Barca are top of La Liga and a threat in the UEFA Champions League again this season, and it's not only because of Messi—even though he's once again having a ridiculous campaign.

Xoel Cardenas explained how Barca may have invested this summer not just for the present, but with an eye on the future, too.

"As weird as it may sound, Barcelona may already have their successor to Messi in Ousmane Dembele.

"With his ability to blow past defenders and create goalscoring chances for his team-mates, Dembele can be moulded into a player that can arguably best succeed Messi when it comes to making Barca better on the pitch overall.

"While he isn't and may never be the goalscorer Leo is, Dembele can learn to do all the other intangibles that make Messi the best in the world.

"At age 20, there's plenty of time for Dembele and his raw talent to not only become a great player but become the great player that fits FC Barcelona's system post-Leo Messi."

It's a train of thought echoed by @YoungCules' Jeffrey, who suggested that going back to the future might be the way forward.

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"Barcelona will most likely have to go back to a traditional three-man attack: two proper wingers and a striker.

"One of the wide positions is of course already settled with Ousmane Dembele, but the other flank and the striker position are still up for grabs."

Dembele hitting his peak and a new top-tier striker—Luis Suarez will likely depart or be past his best before Messi—and suddenly a new-look Barcelona attack looks fearsome again, even without Messi.

But is that as good as one with the No. 10? Perhaps not, meaning Barcelona might still be tempted to bring in further talent from elsewhere.

Seeking answers from beyond

Ask football fans, not just Barcelona fans, to name the best forwards on the planet and there's a fair chance they'll name one who causes the Blaugrana to grit their collective teeth: Neymar, the brilliant Brazilian who swapped the Camp Nou for Paris this past summer.

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As Alex Truica noted, there's a pretty good chance he was already the next best thing to Messi, and he didn't want to be that.

"I think Barcelona had the best possible Messi replacement, but lost him again, in Neymar.

"I don't see anybody else in world football being that complete package of dribbling, creating, passing, scoring. Neymar is the closest thing to Messi.

"So there won't be a direct successor in terms of overall influence on the pitch at Barca. But I can imagine Barcelona going for Juventus' Paulo Dybala soon. He's short, Argentine, left-footed, likes to play in pretty much the same area on the pitch as Messi as well. So there are similarities that might convince Barca to go for Dybala as Messi's successor."

The comparisons between Barcelona's No. 10 and Dybala have been circling for some time, and there's no doubt the Juve man has an abundance of talent.

Stylistically they're not exactly the same, but if you cannot replicate the greatest, the innate qualities Messi offers, changing tack somewhat isn't the worst idea.

And, as our final fan, Dale Anders, pointed out, it might not be just a switch in personnel required, but a complete sea-change to stop inevitable comparisons and pressure on the new face in the team.

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"I would imagine that you'd need three players combined to be the successor to Messi.

"Someone like Christian Eriksen for the passing, [Ousmane] Dembele for the dribbling and Timo Werner for the goals, or maybe Harry Kane.

"No one single player can be the successor to Lionel Messi."

And perhaps that's the most poignant point of all.

When it's finally time for Barcelona to say goodbye to Messi, they won't just be bidding adios to his goals and style, but his aura, the expectation in the crowd, the knowledge that even on a bad day, he's still better than everybody else and can make something happen.

That cumulative effect will be tough to replace, and it might be that a bold new approach to wipe the slate clean is the only way Barcelona can attempt to seamlessly transition into the next era.

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