  We follow the formation of a spin-lattice polaron after a quantum quench that
simulates absorption of the pump{pulse in the time-resolved experiments. We
discover a two-stage relaxation where spin and lattice degrees of freedom
represent an integral part of the relaxation mechanism. In the first stage the
kinetic energy of the spin-lattice polaron relaxes towards its ground state
value while relaxation processes via spin and phonon degrees of freedom remain
roughly independent. In the second, typically much longer stage, a subsequent
energy transfer between lattice and spin degrees of freedom via the charge
carrier emerges. The excess local spin energy radiates away via magnon
excitations.
