diff --git a/litellm/router_strategy/complexity_router/cache_warming/refresher.py b/litellm/router_strategy/complexity_router/cache_warming/refresher.py
index 6bb80233c4d..1161e422a75 100644
--- a/litellm/router_strategy/complexity_router/cache_warming/refresher.py
+++ b/litellm/router_strategy/complexity_router/cache_warming/refresher.py
@@ -99,7 +99,13 @@ def _replay_body(
     default would collide every replay onto one entry. The warming marker rides spend_logs_metadata, not
     metadata.tags: tags are an input to deployment selection (enable_tag_filtering makes an unmatched tag
     unroutable) and to policy (_reject_clientside_metadata_tags_check refuses any request carrying them),
-    while spend_logs_metadata exists to label spend rows, which is all this marker is for."""
+    while spend_logs_metadata exists to label spend rows, which is all this marker is for. Fallbacks are disabled at the
+    dispatch site rather than in the body so no key-level or pre-call mutation can re-enable them: everything
+    warming validated -- prompt-cache eligibility, every-member cacheability, deployment affinity, pricing --
+    is a property of the target GROUP, and a fallback substitutes a different group carrying none of it,
+    spending the customer's money to warm nothing. router.py:6157 raises before fallbacks,
+    context_window_fallbacks and content_policy_fallbacks are consulted, so one flag covers all three; a
+    failed replay simply retries next tick."""
     from litellm.litellm_core_utils.core_helpers import get_metadata_variable_name_from_kwargs
     from litellm.proxy.litellm_pre_call_utils import LiteLLMProxyRequestSetup
 
@@ -637,6 +643,7 @@ class CacheWarmingRefresher:
         if admitted is None:
             return False
         data, principal = admitted
+        data["disable_fallbacks"] = True
         try:
             await (
                 llm_router.aanthropic_messages(**data)  # pyright: ignore[reportUnknownMemberType, reportUnknownVariableType]  # factory-generated router surface is legacy-untyped
diff --git a/tests/test_litellm/router_strategy/complexity_router/cache_warming/test_refresher.py b/tests/test_litellm/router_strategy/complexity_router/cache_warming/test_refresher.py
index 1770eabd0dc..4fb1aa88524 100644
--- a/tests/test_litellm/router_strategy/complexity_router/cache_warming/test_refresher.py
+++ b/tests/test_litellm/router_strategy/complexity_router/cache_warming/test_refresher.py
@@ -370,3 +370,14 @@ async def test_a_direct_sdk_session_with_no_recorded_identity_still_warms_unattr
     await tick(llm_router, active=refresher(keys=FakeKeyDirectory({})))
     assert replayed_models(llm_router) == ["smart-claude"]
     assert llm_router.completion_calls[0]["metadata"]["user_api_key_team_id"] is None
+
+
+@pytest.mark.asyncio
+async def test_a_replay_never_falls_back_to_a_group_warming_did_not_validate():
+    """Eligibility, every-member cacheability, affinity and pricing are properties of the target GROUP, so a
+    fallback would substitute a group carrying none of them and spend the customer's money warming nothing."""
+    llm_router, redis = warming_rig(redis=FakeRedisCache())
+    seed_session(redis)
+    await tick(llm_router)
+    assert llm_router.completion_calls, "expected a replay"
+    assert all(call["disable_fallbacks"] is True for call in llm_router.completion_calls)