The extant social undermining literature suggests that employees envy and, consequently, undermine coworkers when they feel that these coworkers are better off and thus pose a threat to their own current status. With the present research, we draw on the sociofunctional approach to emotions to propose that an anticipated future status threat can similarly incline employees to feel envy toward, and subsequently undermine, their coworkers. We argue that employees pay special attention to coworkers’ past development in relation to their own, because faster-rising coworkers may pose a future status threat even if they are still performing worse in absolute terms in the present. With a set of two behavioral experiments (N = 90 and N = 168), we establish that participants react to faster-rising coworkers with social undermining behavior when the climate is competitive (vs. less competitive). We extended these results with a scenario experiment (N = 376) showing that, in these situations, participants extrapolate lower future status than said coworker and thus respond with envy and undermining behavior. A two-wave field study (N = 252) replicated the complete moderated serial mediation model. Our findings help to explain why employees sometimes undermine others who present no immediate threat to their status. As such, we extend theorizing on social undermining and social comparison.