Former Chelsea scout Chris Robinson is pleased to see Stamford Bridge graduate Dujon Sterling ‘doing very well’ at Rangers while explaining Jose Mourinho’s role in the defender’s lack of chances in the Premier League. So versatile is Dujon Sterling that, if Jack Butland ever picks up an injury – heaven forbid – then it would not come as too much of a surprise to learn that the summer signing from Chelsea is pretty comfortable between the sticks too. Rangers signed Sterling as a right-back when his Blues contract expired last summer. The 24-year-old has featured more often in midfield, however,…