This article examines one US high school teacher's attempt to become a coach by enacting what I call "a pedagogy of negation". For this teacher, the challenge of becoming a coach is nested within a wider agenda of social and personal transformation. That agenda is symbolized first in words as she constructs "a language of coaching" to inform her interactions with students and content as well her conception of herself as a teacher. Second, talk is transformed into pedagogical action through, as described by Driver, the "playful work" of ritualized negation. I argue that the phenomenon of negation is a logical sense-making strategy for teachers attempting to realise transformed pedagogical identities. Negation also reveals a range of uncertainties involved in enacting the practice of coaching. As this case reveals, the pedagogy of negation is constructed as a corrective to restrictive and oppressive forms of schooling. It serves as a mechanism for "becoming" a different, presumably better, kind of teacher. And though the results are mixed, this portrait of practice in the midst of change illuminates the complex and reciprocal links between identity and practice entailed in becoming a coach. (Contains 4 notes.)