The lack of appropriate measurement to assess athlete-coach interaction and athletes’ psychological states has historically plagued sport studies research (i.e., an encompassing term for sport psychology, management, sociology, and communication) and may partially explain the lack of empirical research regarding athlete-coach interaction within the emerging field of sport communication. Without valid and reliable tools to assess athlete-coach interactions, understanding the antecedents and outcomes of these relationships, which is a central aim of sport communication research, cannot be accomplished. This article develops and demonstrates validity for a measure of the coach confirmation instrument (CCI) via two studies. In Study 1, an exploratory factor analysis and parallel analysis produced a 15-item, two-factor measure (challenge and acceptance). In Study 2, a confirmatory factor analysis confirmed this two-factor structure had an acceptable-to-good fit using a variety of fit indices. Additionally, preliminary degrees of validity for the CCI were demonstrated through Pearson correlations with athletes’ feeling of being confirmed, coach satisfaction, and perceptions of coach verbal aggression. Collectively, these studies indicate the CCI is a structurally stable measure, which demonstrates good reliability and initial degrees of face, concurrent, convergent, discriminant, and content validity.