Underperforming in a few noteworthy fixtures only cemented pre-formed opinions that he wasn't the right man.

There was plenty of scepticism when in 2014, after years of searching for the perfect centre-back, the Blaugrana's answer was to sign a recently converted left-back in his 30s. In truth, through no fault of his own, the player has faced an uphill battle from the start of his time in Catalonia. That when it really matters, he isn't on Barca's level. Struggles like those in the toughest games led to a prevailing opinion in some sectors that, to quote Catalan supporters, Mathieu no té nivell Barca. Having ended 2014-15 with his strongest run of form in a Barcelona shirt, those strikingly poor summer showings resurfaced old memories of bad nights from a year prior, the clearest example of which was his unwelcomed contribution to Real Madrid's 3-1 Clasico win in October 2014. His habit of switching off played a significant part in Barca conceding four goals against Sevilla in the UEFA Super Cup in August, and also helped Athletic Club score an away goal in a 1-1 Spanish Supercopa draw a week later. The defender's situation at present is a far cry from his difficult start to the season. The Arsenal encounter will be a significant opportunity for the ex-Valencia man to prove his capacity to perform in a match of the highest importance, putting to bed any lingering doubts from previous sub-par displays in big games.

In recent months, the Frenchman has taken a commanding lead over his rivals for the spot as Barcelona's backup centre-back, starting five games in that position since February while Marc Bartra and Thomas Vermaelen were only given token cameos. Jeremy Mathieu will almost certainly be the man trusted with the job. His manager will have to think carefully about who he picks to replace Barca's single most important defender. At the Emirates, Gerard Pique picked up his third Champions League yellow card of the season, ensuring he won't be able to play the rematch against the Gunners. There will be one change forced upon the Asturian however. Luis Enrique is likely to pick his strongest possible XI against the Gunners, the regular starting team that has won him five trophies since 2015, and is more reliable than a Swiss watch. A 2-0 lead from the first leg of Barcelona's Champions League round-of-16 tie with Arsenal is a solid one, but when the Blaugrana line up at the Camp Nou for the second leg on Wednesday, their coach surely won't risk tempting fate.

Showoff vs arsonal full battle