The management of the professions has become increasingly challenging, reflecting the emergence of new work roles in professionalized workplaces. Human Resource Management (HRM) scholars have, however, been slow to study the professions, particularly how the power they derive from ownership interacts with other forms of power. This article explores the use of different forms of power by a profession, general practitioners (GPs), in engaging with a new healthcare role, the physician associate (PA). Despite policy support for the role, we find GPs' employment of the role in primary care is low. This is explained by two GP responses to the introduction of the role: employment denial and subordination. We theorize these responses as deriving from GPs' ownership power, enhancing their managerial and knowledge-based control over PAs. In doing so, we open-up a research avenue in the study of workforce management focused on professions' ownership power.