diff --git a/eval_protocol/pytest/default_single_turn_rollout_process.py b/eval_protocol/pytest/default_single_turn_rollout_process.py
index f8e7a23e..9e85d744 100644
--- a/eval_protocol/pytest/default_single_turn_rollout_process.py
+++ b/eval_protocol/pytest/default_single_turn_rollout_process.py
@@ -2,7 +2,10 @@
 from typing import List
 
 from litellm import acompletion
-from openai.types.chat.chat_completion_message import ChatCompletionMessageToolCall
+from openai.types.chat.chat_completion_message import (
+    ChatCompletionMessageToolCall,
+    FunctionCall,
+)
 
 from eval_protocol.models import EvaluationRow, Message
 from eval_protocol.pytest.types import RolloutProcessorConfig
@@ -18,7 +21,24 @@ async def process_row(row: EvaluationRow) -> EvaluationRow:
         if len(row.messages) == 0:
             raise ValueError("Messages is empty. Please provide a non-empty dataset")
 
-        messages_payload = [{"role": m.role, "content": m.content} for m in row.messages]
+        messages_payload = []
+        for m in row.messages:
+            payload = {"role": m.role}
+            if m.content is not None:
+                payload["content"] = m.content
+            if m.name is not None:
+                payload["name"] = m.name
+            if m.tool_call_id is not None:
+                payload["tool_call_id"] = m.tool_call_id
+            if m.tool_calls is not None:
+                payload["tool_calls"] = [
+                    tc.model_dump(exclude_none=True) for tc in m.tool_calls
+                ]
+            if m.function_call is not None:
+                payload["function_call"] = m.function_call.model_dump(
+                    exclude_none=True
+                )
+            messages_payload.append(payload)
 
         request_params = {"model": config.model, "messages": messages_payload, **config.input_params}
 
@@ -27,8 +47,10 @@ async def process_row(row: EvaluationRow) -> EvaluationRow:
 
         response = await acompletion(**request_params)
 
-        assistant_content = response.choices[0].message.content or ""
-        tool_calls = response.choices[0].message.tool_calls if response.choices[0].message.tool_calls else None
+        assistant_message = response.choices[0].message
+        assistant_content = assistant_message.content or ""
+        tool_calls = assistant_message.tool_calls if assistant_message.tool_calls else None
+        function_call = assistant_message.function_call
 
         converted_tool_calls = None
         if tool_calls:
@@ -49,6 +71,7 @@ async def process_row(row: EvaluationRow) -> EvaluationRow:
                 role="assistant",
                 content=assistant_content,
                 tool_calls=converted_tool_calls,
+                function_call=function_call,
             )
         ]
 
diff --git a/tests/test_default_single_turn_rollout_processor.py b/tests/test_default_single_turn_rollout_processor.py
new file mode 100644
index 00000000..28e61c45
--- /dev/null
+++ b/tests/test_default_single_turn_rollout_processor.py
@@ -0,0 +1,74 @@
+import asyncio
+from types import SimpleNamespace
+from typing import Any, Dict, List
+from unittest import mock
+from openai.types.chat.chat_completion_message import (
+    ChatCompletionMessageToolCall,
+    ChatCompletionMessageToolCallFunction,
+)
+
+from eval_protocol.models import EvaluationRow, Message
+from eval_protocol.pytest.types import RolloutProcessorConfig
+from eval_protocol.pytest.default_single_turn_rollout_process import (
+    default_single_turn_rollout_processor,
+)
+
+
+def test_handles_function_call_messages() -> None:
+    async def run_test() -> None:
+        tool_call = ChatCompletionMessageToolCall(
+            id="call_1",
+            type="function",
+            function=ChatCompletionMessageToolCallFunction(
+                name="get_weather", arguments="{}"
+            ),
+        )
+        row = EvaluationRow(
+            messages=[
+                Message(role="user", content="Hi"),
+                Message(role="assistant", tool_calls=[tool_call], content=""),
+                Message(role="tool", tool_call_id="call_1", content="sunny"),
+            ],
+            tools=[{"type": "function", "function": {"name": "get_weather"}}],
+        )
+        config = RolloutProcessorConfig(
+            model="gpt-4o-mini", input_params={}, mcp_config_path=""
+        )
+
+        captured_messages: List[Dict[str, Any]] = []
+
+        async def fake_acompletion(**kwargs: Any) -> Any:
+            nonlocal captured_messages
+            captured_messages = kwargs["messages"]
+            return SimpleNamespace(
+                choices=[
+                    SimpleNamespace(
+                        message=SimpleNamespace(
+                            content="done",
+                            tool_calls=[
+                                ChatCompletionMessageToolCall(
+                                    id="call_2",
+                                    type="function",
+                                    function=ChatCompletionMessageToolCallFunction(
+                                        name="foo", arguments="{}"
+                                    ),
+                                )
+                            ],
+                            function_call=None,
+                        )
+                    )
+                ]
+            )
+
+        with mock.patch(
+            "eval_protocol.pytest.default_single_turn_rollout_process.acompletion",
+            side_effect=fake_acompletion,
+        ):
+            dataset = await default_single_turn_rollout_processor([row], config)
+
+        assert captured_messages[1]["tool_calls"][0]["id"] == "call_1"
+        assert captured_messages[2]["tool_call_id"] == "call_1"
+        result_row = dataset[0]
+        assert result_row.messages[-1].tool_calls[0].id == "call_2"
+
+    asyncio.run(run_test())