diff --git a/bbreplay/replay.py b/bbreplay/replay.py
index e82f83f..e5dbb46 100644
--- a/bbreplay/replay.py
+++ b/bbreplay/replay.py
@@ -248,8 +248,7 @@ def _process_kickoff(self, cmds, log_entries, board):
             board.blitz()
             yield from self._process_turn(cmds, log_entries, board, False)
         elif kickoff_result == KickoffEvent.PITCH_INVASION:
-            # XXX: Players may get stunned, but we've not currently got any examples so we need to check what happens
-            pass
+            raise NotImplementedError("Cannot process 'Pitch Invasion' event because injured players aren't identified")
         else:
             raise NotImplementedError(f"{kickoff_result} not yet implemented")