The England international joined City last summer from Everton for a fee of £47.5 million, making him the second-most expensive defender in the history of the game.
Working under Guardiola, the signs were positive for Stones early in his City career, as the youngster adapted well to the coach's principles; the former Toffees star is composed and confident on the ball, which marries perfectly with the Catalan's methods.
However, as the season has rumbled on, the 22-year-old has started to struggle. The centre-back has been caught out on numerous occasions being a little too casual with the ball, most notably in the 4-2 loss to Leicester City and the 1-1 draw with Southampton, as opponents latched on to loose passes of his to score.
Despite his inconsistent form, when Stones is injured, it's a problem for City. After all, captain Vincent Kompany has struggled to stay fit for some time; Nicolas Otamendi is the only other natural centre-back, with left-back Aleksandar Kolarov filling in at times with mixed results.
Not only is Stones one of City's best options in the position, the more he plays, the quicker his development will be. With that in mind, Guardiola will be desperate for the defender to return soon.