Objective: Using diffusion tensor imaging (DTI), researchers have reported decreased in fractional anisotropy (FA) in the brain immediately following sport-related concussion (SRC), whereas others have reported increased FA at later time points following SRC. The purpose of the current study was to compare DTI in relation to functional impairment at sub-acute and recovered time points following SRC. Method: Fourteen athletes (9 males, 5 females) aged 17.1 years +/− 3.1 with a diagnosed SRC participated in the study. Participants completed the Sideline Assessment of Concussion (SAC), Immediate Post-concussion Assessment and Cognitive Testing (ImPACT), Post-concussion Symptom Scale (PCSS), Vestibular/Ocular Motor Screen (VOMS), Dizziness Handicap Inventory (DHI), Balance Error Scoring System (BESS), Functional Gait Assessment (FGA) and also underwent DTI between 1–14 days post injury (i.e., sub-acute; n= 9) or when medically cleared for full activity (i.e., recovered; n= 5). A p < .05 was used for t-tests and correlations. Results: FA in the left thalamus was lower in the sub-acute (.37 +/−.02) compared to the recovered (.40 +/-.03) group. Correlations were supported for decreased FA in the thalamus and increased DHI (−.60), convergence distance (–.60), and reaction time (–.54); and decreased visual memory (.54) and processing speed (.61). Positive correlations were supported for recovery time and FA in the cerebellum (.98) and hippocampus (.95). Conclusion: Decreased FA in the thalamus was associated with functional impairment and symptoms. Reported decreases in FA for the sub-acute compared to the recovered group as well as the associations between recovery time and FA suggest that DTI may be dependent on time since injury.