A pop-up rotor-type irrigation sprinkler includes an outer case and a riser assembly telescopically extensible from the outer case. A coil spring surrounds the riser assembly and normally holds the riser assembly in a lower retracted position within the outer case. The coil spring is dimensioned and configured to permit extension of the riser assembly to a raised upper position when pressurized water is introduced into the outer case. A cushion made of an elastomeric material is retained in the outer case adjacent an end thereof and surrounds the riser assembly. The cushion may be solid and may move between hard structures to facilitate absorption of the shock of the impact caused by rapid extension of the riser assembly to its raised upper position. The cushion may also include a plurality of voids that facilitate deformation and shock absorption.