#7 Sergio Busquets
Guardiola took a major punt when he discarded Yaya Toure and installed an untested Sergio Busquets as his preferred choice in defensive midfield and there were more than a few who expressed disdain, preferring the more established Ivory Coast international.
However, the Catalan manager had coached Busquets at junior level and seemingly saw his requirements in the youngster and a few years later, his decision has been justified, with the Spaniard going on to cement his legacy as one of the greatest holding midfielders in history.
Although he lacks the flair and skillset of some of his more attack-minded teammates, the importance of Busquets to the success of Barcelona should not be underrated and keen observers are usually in awe of how effortlessly he makes the most difficult of tasks look routine.
The 31-year-old is one of the most decorated players of his generation and has enjoyed immense success with both Spain and Barcelona and although not particularly renowned for his goalscoring prowess (he has scored just 15 goals in the colours of Barcelona), the fact that he has been a mainstay amidst a pool of extremely talented midfielders is indicative of his ability.