Roles (i.e., sets of behavioural expectations for team members) constitute an important structural aspect of sport teams (Carron & Eys, 2012). Previous research has demonstrated that positive role-related perceptions (e.g., clarity, acceptance) are critical for effective team functioning, though this body of research focused mostly on formal roles that are typically prescribed by coaches (e.g., captainship, playing positions; Eys et al., 2014). Recent literature suggested that various informal roles (i.e., those that emerge more naturally without coach assignment) such as team comedians, mentors, and distracters may also have important ramifications for sport team functioning and athlete experiences (e.g., Cope et al., 2011). The purpose of the current study was to assess how perceptions of informal role occupancies influence group cohesion (Carron et al., 1985), athlete satisfaction (Riemer & Chelladurai, 1998), and intentions to return (Spink, 1995) in sport teams. Data were collected from 16 intercollegiate teams at two time points (NT1 = 231, NT2 = 203; 1-2 weeks apart). The results revealed that the number of teammates that athletes nominated as occupants of informal roles at time 1 predicted several dimensions of outcome variables at time 2 (e.g., athletes' intentions to return to the team were positively predicted by the number of teammates they nominated as mentors, ? = .18, p = .001, and negatively predicted by the number of teammates they nominated as distracters, ? = -.13, p = .006). These findings provide statistical evidence that supports the importance of informal role structures within interdependent sport team settings.