What is behind the mental fragility that causes Barca paralysis?

The one word uppermost in the minds of all Barcelona players, fans and pundits throughout this season was ‘Roma’.

Barca’s shock 0-3 defeat at Roma in last year’s Champions League quarter-final second leg marked the collective Camp Nou psyche — even taking the gloss of winning the 2017/18 La Liga and Copa del Rey double, especially when rivals Real Madrid went on to lift the UCL trophy.