Just over a year ago, Barcelona were floundering. The signing of Luis Suarez had done nothing to improve the fortunes of a team which failed to land any silverware at the end of the previous season, and manager Luis Enrique was facing increasing pressure after overseeing an unconvincing series of performances.

Everything turned, however, in the course of one game in early January, when Barca finally found a sense of direction and purpose.

Barca won 3-1, Messi, Suarez and Neymar all got onto the scoresheet for the very first time, and the rest is history. The vanquished opponents were none other than Atletico Madrid. And on Saturday, the latest rematch with Diego Simeone’s side will provide the biggest clue yet as to whether the ‘MSN’ forward line will dominate world football in 2016 as they did in 2015.

Make no mistake, Barcelona possess a wonderful squad. But Andres Iniesta, Sergio Busquets, Gerard Pique and the rest are the sub-plot: the thing that sets them apart is Messi, Suarez and Neymar – both individually and for their brilliant combination play, making them close to unstoppable.

MSN’s ability to rescue their team was seen as recently as Wednesday, when Barca were struggling in their Copa del Rey clash with Athletic Bilbao until Messi crossed for Suarez to score and the tie turned decisively in their favour. Can they be stopped? If any team can, it is surely Atletico, who have conceded just three goals in their opening 11 away league games this season – something never achieved before.

Atletico’s defensive excellence begins with the seriously under rated Diego Godin, the Uruguayan central defender who is a model of consistency and reliability. Godin sets the tone for Atletico’s defending by doing just that: defending.

Unlike Barca’s back four, who are responsible for starting attacks just as much as ending those of the opposition, Godin does not care too much where the ball goes once he clears it. He just gets it out of the danger zone, taking no chances, and backs himself to clear it again when it comes back. It is almost an ‘anti-Barca’ approach but Atletico do it brilliantly, relying on their organisation, determination and mental resilience to repel anything thrown at them.

And their organisation, masterminded by Simeone’s attention to detail, is another key element. However the opposition attacks them – whether they play the ball along the ground or in the air, long or short – Atletico’s positioning is so solid, their collective movement so well-rehearsed, it can be impossible to find space.

They surround, smother, frustrate and, when the ball presents itself, get rid of it. Atletico’s defence is not infallible, as demonstrated by Barca’s recent successes against them, but they present the biggest possible challenge to attackers.

If Godin and company claim another clean sheet today, it could swing the title race decisively in Atletico’s direction. That’s a very big ‘if’, but don’t rule it out.