Purpose The purpose of this study was to evaluate changes in cognitive-communication performance using Woodcock-Johnson IV Tests (WJIV) from pre-injury baseline to post sport-related concussion. It was hypothesized that individual subtest performances would decrease postinjury in symptomatic individuals. Method This prospective longitudinal observational nested cohort study of collegiate athletes assessed cognitive-communicative performance at preseason baseline and postinjury. Three hundred and forty-two male and female undergraduates at high risk for sport-related concussion participated in preseason assessments, and 18 individuals met criteria post injury. WJIV subtest domains included Word Finding, Speeded Reading Comprehension, Auditory Comprehension, Verbal Working Memory, Story Retell, and Visual Processing (letter and number). The power calculation was not met, and therefore data were conservatively analyzed with descriptive statistics and a planned subgroup analysis based on symptomatology. Results Individual changes from baseline to postinjury were evaluated using differences in standard score performance. For symptomatic individuals, mean negative decreases in performance were found for Retrieval Fluency, Sentence Reading Fluency, Pattern Matchings, and all cluster scores postinjury. Individual performance declines also included decreases in story retell, verbal working memory, and visual processing. Conclusions This study identified within-subject WJIV performance decline in communication domains post sport-related concussion and reinforces that cognitive-communication dysfunction should be considered in mild traumatic brain injury. Key cognitive-communication areas included speeded naming, reading, and verbal memory, though oral comprehension was not sensitive to change. Future clinical research across diverse populations is needed to expand these preliminary findings.