A small gauge surgical instrument assembly is shown with advantages such as diminished “play” at the tip. A surgical instrument assembly is also shown with support along a length of the instrument that can be selected by the surgeon. In particular, very small and flexible instruments for vitreous surgery are shown with selectable stiffness, thus providing control as well as access to all parts of the vitreous cavity. Embodiments as shown are safer, and increase the variety of cases for which these instruments can be used.