Human-aware robot navigation addresses the navigation of the robot in the presence of humans. Although significant research exists for addressing the visible humans, there is a need to address the humans that are not visible but can emerge anytime into the scene. While addressing such 'invisible humans', we have to make sure to avoid surprises or shocks for humans and the erratic behavior of the robot planner. In this work, we propose a novel approach to detect and integrate these 'invisible humans' into human-aware navigation planning. The experiments and the results presented show the advantage of the proposed idea.