Analysing the 367 member replacement acts in the 2014 FIFA World Cup tournament, we uncover important dynamics between member replacement and team performance. We find that poor team performance leads to substitutions with more competence gains (or with less competence loss), that substituting and substituted members’ functional background dissimilarity improves subsequent content-related team performance (i.e. scoring more goals), and that their competence superiority is associated with the speed of team performance turnaround (i.e. scoring goals faster). Going beyond contrasts between teams with and without membership change, the paper highlights the importance of substituting and substituted members’ relative task-related attributes and provides a more nuanced understanding of the complex phenomenon of team membership change. Furthermore, the paper extends the methodological spectrum of dynamic team composition research from predominantly laboratory experiments with short-lived student groups performing cognitive tasks to field studies with real-life work teams performing action tasks.