X-ray assisted nuclear excitation by electron capture (NEEC) into inner-shell atomic holes in a plasma environment generated by strong optical lasers is investigated theoretically. The considered scenario involves the interaction of a strong optical laser with a solid-state nuclear target leading to the generation of a plasma. In addition, intense x-ray radiation from an X-ray Free Electron Laser (XFEL) produces inner-shell holes in the plasma ions, into which NEEC may occur. As case study we consider the 4.85-keV transition starting from the 2.4 MeV long-lived 93m Mo isomer that can be used to release the energy stored in this metastable nuclear state. We find that the recombination into 2p 1/2 inner-shell holes is most efficient in driving the nuclear transition. Already at few hundred eV plasma temperature, the generation of inner-shell holes can allow optimal conditions for NEEC, otherwise reached for steady-state plasma conditions in thermodynamical equilibrium only at few keV. The combination of x-ray and optical lasers presents two advantages: first, NEEC rates can be maximized at plasma temperatures where the photoexcitation rate remains low. Second, with mJclass optical lasers and an XFEL repetition rate of 10 kHz, the NEEC excitation number can reach ∼ 1 depleted isomer per second and is competitive with scenarios recently envisaged at petawattclass lasers.