diff --git a/pymodbus/client/base.py b/pymodbus/client/base.py
index a91efc618c..63cf8732bc 100644
--- a/pymodbus/client/base.py
+++ b/pymodbus/client/base.py
@@ -130,7 +130,7 @@ def __init__(  # pylint: disable=too-many-arguments
         )
         self.reconnect_delay = self.params.reconnect_delay
         self.reconnect_delay_current = self.params.reconnect_delay
-        self.use_protocol = False
+        self.use_sync = False
         self.use_udp = False
         self.state = ModbusTransactionState.IDLE
         self.last_frame_end: float = 0
@@ -175,13 +175,13 @@ def execute(self, request: ModbusRequest = None) -> ModbusResponse:
         :returns: The result of the request execution
         :raises ConnectionException: Check exception text.
         """
-        if self.use_protocol:
-            if not self.transport:
-                raise ConnectionException(f"Not connected[{str(self)}]")
-            return self.async_execute(request)
-        if not self.connect():
-            raise ConnectionException(f"Failed to connect[{str(self)}]")
-        return self.transaction.execute(request)
+        if self.use_sync:
+            if not self.connect():
+                raise ConnectionException(f"Failed to connect[{str(self)}]")
+            return self.transaction.execute(request)
+        if not self.transport:
+            raise ConnectionException(f"Not connected[{str(self)}]")
+        return self.async_execute(request)
 
     # ----------------------------------------------------------------------- #
     # Merged client methods
diff --git a/pymodbus/client/serial.py b/pymodbus/client/serial.py
index beefdd112c..20224a6da3 100644
--- a/pymodbus/client/serial.py
+++ b/pymodbus/client/serial.py
@@ -61,7 +61,6 @@ def __init__(
     ) -> None:
         """Initialize Asyncio Modbus Serial Client."""
         super().__init__(framer=framer, **kwargs)
-        self.use_protocol = True
         self.params.port = port
         self.params.baudrate = baudrate
         self.params.bytesize = bytesize
@@ -158,6 +157,7 @@ def __init__(
         self.params.stopbits = stopbits
         self.params.handle_local_echo = handle_local_echo
         self.socket = None
+        self.use_sync = True
 
         self.last_frame_end = None
 
diff --git a/pymodbus/client/tcp.py b/pymodbus/client/tcp.py
index 52ab59ad65..df77724c60 100644
--- a/pymodbus/client/tcp.py
+++ b/pymodbus/client/tcp.py
@@ -47,7 +47,6 @@ def __init__(
     ) -> None:
         """Initialize Asyncio Modbus TCP Client."""
         super().__init__(framer=framer, **kwargs)
-        self.use_protocol = True
         self.params.host = host
         self.params.port = port
         self.params.source_address = source_address
@@ -140,6 +139,7 @@ def __init__(
         self.params.port = port
         self.params.source_address = source_address
         self.socket = None
+        self.use_sync = True
 
     @property
     def connected(self):
diff --git a/pymodbus/client/udp.py b/pymodbus/client/udp.py
index 1d7ef71cb6..112e7da3e7 100644
--- a/pymodbus/client/udp.py
+++ b/pymodbus/client/udp.py
@@ -50,7 +50,6 @@ def __init__(
     ) -> None:
         """Initialize Asyncio Modbus UDP Client."""
         super().__init__(framer=framer, **kwargs)
-        self.use_protocol = True
         self.params.host = host
         self.params.port = port
         self.params.source_address = source_address
@@ -138,6 +137,7 @@ def __init__(
         self.params.source_address = source_address
 
         self.socket = None
+        self.use_sync = True
 
     def connect(self):  # pylint: disable=invalid-overridden-method
         """Connect to the modbus tcp server.