Large gaze shifts necessitate intricate eye-head coordination. High-frequency bursts of activity within the superior colliculus (dSC) encode desired gaze shifts regardless of component movements of the eyes and head. However, it remains unclear whether low-frequency activity emitted throughout the oculomotor system, including the dSC, play any role in eye-head gaze shifts. Here, we test whether such low-frequency activity selectively primes head premotor circuits. We exploited the capacity for short-duration (10 ms) dSC stimulation to evoke neck muscle responses without compromising ocular stability, stimulating at various intervals of a gap-saccade task associated with known low-frequency fluctuations throughout the oculomotor system. Stimulation was passed during the initial fixation-interval, a 200 ms gap-interval between fixation point offset and target onset, or during a movement-interval following target onset. In two monkeys, evoked responses on multiple muscles tracked known fluctuations in low-frequency oculomotor activity, being greater following gap- versus fixation-interval stimulation, and greater still when the location of stimulation during the movement interval coincided with the area of the dSC generating the ensuing saccade. In one monkey, we obtained a more detailed timeline of how these results co-varied with low-frequency oculomotor activity. Importantly, in both monkeys, baseline levels of neck EMG did not co-vary with low-frequency oculomotor activity. We conclude that low-frequency oculomotor activity primes head premotor circuits well in advance of gaze shift initiation in a manner distinct from its effects on the eye premotor circuits. Such distinctions presumably aid the temporal coordination of the eyes and head despite fundamentally different biomechanics.