In the first 53 years of the European Cup, just four clubs managed to add the continental crown to landing their domestic league and cup titles. The treble was viewed as a barely conceivable objective that even for the very best clubs might come around once in a generation. Yet four more trebles have been achieved in just the last seven seasons. And now Barcelona have a real chance to become the first team ever to complete a clean sweep of major honors in back-to-back seasons.

It is evident that in the age of the super-clubs, where financial wealth and the world’s top players are increasingly concentrated at a select few teams, the level of domination required to win a treble is becoming more prevalent. Still, were Barcelona to win the Champions League, La Liga and Copa del Rey again this season, they would be fully deserving of all the praise that comes their way, including figuring prominently in the conversation of the greatest teams of all time.

Such lofty talk would have been hard to envisage exactly 12 months ago. Then Barcelona were coming off a defeat to Real Sociedad and ructions that left the club staring at a full-blown crisis. Lionel Messi, along with Neymar, had been left on the bench for his team’s first match back after the winter break, and had then missed an open training session the following day, fueling rumors of a major falling out between star player and first-year Barcelona coach Luis Enrique. Meanwhile, sporting director Andoni Zubizarreta was dismissed and his deputy Carles Puyol stepped down. It was thought that Enrique would be lucky to even see out the season, while president Josep Maria Bartomeu’s exit might not be far behind.

At the time, Barcelona were beginning a year-long transfer ban and their big signing of the previous summer, Luis Suárez, had scored just three goals in his first 12 appearances. The turnaround from that low ebb was as spectacular as it was unexpected. Enrique learned that, while he had the title of the boss, he would have to take a different approach with four-time Ballon d’Or winner Messi. And he appeared to listen to his players, too, regarding the crucial tactical adjustment that would transform the team’s fortunes.

Luis Enrique Luis Enrique recovered from a difficult start at Barcelona to lead the team to five trophies in 2015. Photo: Getty Images

As Suárez described it, during one particular game, Messi told the Uruguayan, who had previously been operating mainly from the right flank, to stay as the central striker. Enrique, seeing the positive impact of the switch, decided to stick with it. And the rest is history. Since then, Messi, Suárez and Neymar have gone onto form surely the most devastating forward trio ever seen.

Not only are they as individuals three of the very best players in the world —indeed, there is a strong argument that they should fill out the podium at his month’s Ballon d’Or — but they have adapted their games for the good of each other and the team. Messi, whose presence appeared to damage the progress of previous Barcelona strikers David Villa and Zlatan Ibrahimovic, has happily moved back to the right and become more of a playmaker, Neymar has added formidable interplay to his samba skills, while Suárez’s selfless running has opened space for his forward colleagues to revel in.

Barcelona were the dominant team in Europe last season, and there is plenty to suggest they could be again this campaign. Certainly it is hard not to think that Enrique would have happily taken Barcelona’s current position had it been offered to him at the start of the campaign.

It was far from the smoothest of beginnings to the season. A rash of injuries had weakened a squad that had already been thinned by the summer exits of Xavi and Pedro and could not yet be boosted by new signings Arda Turan and Aleix Vidal. Meanwhile, the Catalans faced a punishing first half of the season that would see them travel away to title rivals Real Madrid and Atlético Madrid as well as Valencia and Sevilla. Thrown in there, too, was a trip to Japan for the Club World Cup.

Yet, despite all those challenges, Barcelona are thriving and have already added the title of world champions to their collection. Should they win their game in hand they would leapfrog Atlético Madrid to go back to the top of the Primera Division table and move five points ahead of a Real Madrid team that has just been unsettled by a change of coach. They are also safely into the last 16 of the Champions League, where they will take on an Arsenal side they have beaten twice in recent seasons. And on Wednesday they will step up their challenge to retain the Copa del Rey when hosting local rivals Espanyol in the first leg of their Round of 16 tie.

Arda Turan After signing from Atlético Madrid last July, Turkey international Arda Turan can now make his long-awaited debut for Barcelona. Photo: Getty Images

And further reason for optimism comes from the fact that Turan and Vidal will be able to pull on a Barcelona shirt in a competitive matchup for the first time. Enrique has confirmed both summer signings, who have now been registered, will play a part at the Camp Nou on Wednesday.

Boosted by that squad depth, it is difficult to see any team being their match in Spain. In Europe things will be tougher. Bayern Munich are flying and will want to give manager Pep Guardiola a winning sendoff before he leaves his post. But Barcelona had far too much for the German champions in last year’s semifinals. Few would bet against the Champions League final in Milan on May 28 proving a historic occasion, where Barcelona could not only become the first team to win back-to-back trebles, but also the first repeat winners of the Champions League.