What happens when your robot teammate excludes you? As automation reshapes the workplace, understanding social dynamics in human–robot teams is more important than ever. Grounded in the Temporal Need-Threat Model, this preregistered study examines how coworker behavior (inclusion vs. ostracism-based exclusion) and agent type (human, humanoid robot, industrial robot) affect psychological needs, compensatory behavior, and social reasoning in a manufacturing context. Across 117 participants, ostracism significantly threatened core needs (belonging, self-esteem, and meaningful existence) and reduced motivation to engage in compensatory efforts (e.g., becoming more pleasant). These effects were strongest when exclusion came from a human coworker, and weakest when it came from an industrial robot. While compensatory efforts decreased under ostracism, their perceived effectiveness remained highest for human coworkers. Ostracizing humans were also penalized most in perception, receiving lower ratings on likability and intelligence than robot agents. Perceived anthropomorphism intensified both need satisfaction and need-threat, depending on context. Open-ended responses revealed distinct attribution patterns: human exclusion was interpreted as personal (e.g., dislike), whereas robot exclusion was interpreted as a mechanical or programming issue. These findings challenge the assumption that robots are treated like humans in social settings (CASA) and highlight the double-edged role of anthropomorphism. The study offers novel insights into how team dynamics shift in hybrid human–robot workplaces and underscores the need to manage expectations in collaborative automation design for safeguarding psychological needs in increasingly automated workplaces.