By Tom Gott Gerard Pique shocked the world earlier this week when, out of nowhere, he confirmed he would walk away from Barcelona after Saturday’s visit from Almeria. The 35-year-old is deservedly seen as one of the greatest centre-backs of all time, having won everything there is to win in Spanish football – both for club and country – but few expected to see him hang up his boots in such abrupt fashion. Here’s a closer look at what’s going on. His promise to himselfTo understand Pique’s departure from Barcelona, it’s important to focus on an interview the centre-back gave with El Pais in Oct…