This study builds upon the methodological framework established by Castelnuovo et al. (2023) to analyze the influence of the intervention context (market) on professional psychological practice. Despite ongoing efforts to define psychologist, clinical psychologist, and psychotherapist roles, we argue that these definitions are insufficient to safeguard both professional practice and client well-being. Regulatory frameworks contained by intervention contexts can create conditions that limit the scope of psychological practice. This limitation stems from the introduction of “other players” and the roles assigned to them by regulations. This can lead to a concerning marginalization of core psychological functions, such as diagnosis. We demonstrate that intervention context significantly impacts the profession’s scope, influencing crucial aspects like the diagnostic function. The legal context is presented as a specific example for further discussion.