55Mn NMR experiments have been performed at 4.2 K on a series of Mn(GeSi) epitaxial films () to investigate changes introduced by silicon when it replaces germanium in a hexagonal MnGe crystal lattice. The Si/Ge substitution was found to reduce the magnetic moment on manganese located in the 6(g) sublattice creating a new population of manganese atoms with distinctly lower magnetic moment. This effect is attributed to the orbital overlay due to a lattice distortion introduced by Si. Interestingly, these modified Mn sites retain the orbital moment practically unaltered. The amount of new manganese environments in the 6(g) sublattice coincides with a probability of Mn having two Si neighbors as first neighbors. Mn atoms located in the 4(d) sublattice are not significantly affected by the Si substitution in the studied concentration range.