Since MİLDEN will come somewhat late, we should consider short-range SLBM capability with TAYFUN. Either a larger MİDLAS or a smaller TAYFUN missile.
It has already been said that MILDEN will come with such a capability, it will be up to Roketsan (and indirectly SSB who will fund the project) to make these missiles and launchers compatible with the given space/volume. In short term it is for Gezgin, but if Navy is interested in MRBM capability, it can be incorporated as well.