A headrest assembly according to an exemplary aspect of the present disclosure includes, among other things, a rod configured to connect the headrest assembly to a seat back. The rod includes a first vertical portion and a second vertical portion, which each have a plurality of recesses. The headrest assembly further includes a head restraint including a pushing plate having a first locking portion and a second locking portion. The first and second locking portions selectively engage the recesses of the first and second vertical portions, respectively, to adjust a vertical position of the head restraint.