Recent experimental and theoretical work has confirmed that, under certain processing conditions, discontinuous subgrain growth (DSG) occurs in deformed high stacking fault energy alloys such as aluminium, nickel and iron. It was shown that, during annealing, a small number of subgrains grow rapidly to consume the surrounding substructure in a manner analogous to secondary recrystallization. This phenomenon was attributed to the orientation dependence of low angle boundary energies and mobilities. In the present work, {110}<001>-oriented aluminium single crystals were deformed in plane strain compression (PSC) and lightly annealed to study the origin of DSG using TEM and SEM/EBSD. It was found that, while the {110}<001> orientation is predicted to be highly stable during PSC, deformation was not as uniform on a microscale with the development of localised regions of microstructure exhibiting a large spread in subgrain orientations. TEM evidence indicates that deformation does not occur uniformly on all four of the active slip systems in this crystal, but may occur by a combination of single and coplanar slip to produce orientation perturbations throughout the microstructure. These locally perturbed regions are argued to be favourable sites for rapid growth of subgrains, which is consistent with the proposed conditions for DSG in the earlier work.