The team has become a popular model to organize joint human–robot behavior. Robot teammates are designed with high-levels of autonomy and well-developed coordination skills to aid humans in unpredictable environments. In this paper, we challenge the assumption that robots will succeed as teammates alongside humans. Drawing from the literature on human teams, we evaluate robots’ potential to meet the requirements of successful teammates. We argue that lacking humanlike mental models and a sense of self, robots may prove untrustworthy and will (...) be rejected from human teams. Benchmarks for evaluating human–robot teams are included, as are guidelines for defining alternative structures for human–robot groups. (shrink)