This study investigates an under-developed research area, sports partnership management, to deepen the understanding of the strategic implications derived from a sports club’s partnerships. A relationship perspective to the portfolio framework is employed by considering the complexity of a partnership as the managerial input variable, and the value impact of the partnership as the output variable. It adopts a longitudinal single case study design, allowing aspects of both exploration and explanation through evidence from multiple sources within the organization. The data collection entails a three-phase empirical research process, collecting data from different sources within a professional sports club. Based on a dataset containing two waves of contract data collected in Phase 2 coupled with interviews in Phase 1 and discussions in Phase 3, this research provides three meaningful applications of a partnership portfolio framework. Theoretically, this research provides insights into enhancing the rigor of the operationalization of a portfolio analysis by paying particular attention to the validity of the portfolio framework and its measurement issues. Practically, the study offers a framework for analyzing its partnership portfolio that provides insights into the current status of the portfolio and ways to build, sustain and/or improve the management of their partnerships.