Background: A nonconcussive injury occurs from an impact to the head that does not result in overt symptoms. However, growing evidence suggests that the accumulation of nonconcussive impacts can result in neurological symptoms, either due to injury to the blood vessel or as a result of altered neural functioning. Despite this, the effects of repeated nonconcussive impacts on cerebral blood flow (CBF) and cerebrovascular reactivity (CVR) remain unclear. Methods: Twenty Canadian male collegiate football athletes were imaged at three time points: pre-, mid-, and post-season (3T Siemens Prisma) with arterial spin labelling (CBF) and a blood oxygen level-dependent sequence during which hypercapnia was induced (CVR; RA-MR, Thornhill Medical, Toronto, CA). Results: Significant changes in CBF and CVR were observed at both mid- and post-season compared to pre-season baseline measurements. Conclusions: Alterations in CBF and CVR may precede the emergence of neurocognitive symptoms later in life that may be associated with repetitive nonconcussive impacts. These findings highlight the potential of CBF and CVR as early biomarkers for trauma-related brain changes in contact sports. Future studies should investigate the long-term consequences of these physiological alterations and implement player safety protocols designed to reduce the prevalence of nonconcussive impacts.