diff --git a/litellm/router.py b/litellm/router.py
index fc4f2d227f5..b1038ca6002 100644
--- a/litellm/router.py
+++ b/litellm/router.py
@@ -12636,6 +12636,8 @@ class Router:
         registered_model_name: str,
         request_kwargs: Mapping[str, object],
     ) -> str:
+        if not any((self.auto_routers, self.complexity_routers, self.adaptive_routers, self.quality_routers)):
+            return registered_model_name
         cache_key: Final = self._claude_code_session_router_cache_key(request_kwargs)
         if cache_key is None or not isinstance(request_kwargs, dict):
             return registered_model_name
diff --git a/tests/test_litellm/test_router.py b/tests/test_litellm/test_router.py
index 05dcb664ed5..ef25502a4f9 100644
--- a/tests/test_litellm/test_router.py
+++ b/tests/test_litellm/test_router.py
@@ -8499,6 +8499,26 @@ class TestClaudeCodeSubagentSessionRouterBinding:
         assert response is None
         redis_cache.async_delete_cache.assert_awaited_once()
 
+    @pytest.mark.asyncio
+    async def test_no_pre_routing_strategies_means_no_session_cache_traffic(self):
+        from litellm.caching.caching import RedisCache
+
+        router = self._router()
+        router.complexity_routers = {}
+        redis_cache = MagicMock(spec=RedisCache)
+        redis_cache.async_get_cache = AsyncMock(return_value=None)
+        redis_cache.async_set_cache = AsyncMock()
+        redis_cache.async_delete_cache = AsyncMock()
+        router._update_redis_cache(cache=redis_cache)
+
+        for request_kwargs in (self._request_kwargs(), self._request_kwargs(agent_id="agent-1234")):
+            response = await router.async_pre_routing_hook(model="expensive-model", request_kwargs=request_kwargs)
+            assert response is None
+
+        redis_cache.async_get_cache.assert_not_awaited()
+        redis_cache.async_set_cache.assert_not_awaited()
+        redis_cache.async_delete_cache.assert_not_awaited()
+
     @pytest.mark.asyncio
     async def test_session_bindings_do_not_evict_router_rate_limit_state(self):
         router = self._router()