This paper proposes a conceptual framework for redefining the role of social robots in the context of sustainability. Current approaches focus mainly on persuasive models that aim to change users’ behaviour towards sustainability, positioning the robot as a behaviour-shaping agent. Instead, this work suggests an alternative, non-reductionist model grounded in the relational, embodied, and epistemological dimensions of social robotics. A sustainable role is here defined as one that emerges from the intersection of three core criteria: the type of social robot (conceived as a connector that fosters social cohesion), its material and expressive embodiment (ethically and ecologically responsible), and the form of human-robot relationship (based on partnership and emergent behaviors rather than control or persuasion). This framework not only advances a more ethically grounded vision of social robotics but also offers guidelines for assessing and designing socially sustainable robotic systems that support inclusion, cooperation, and shared agency.