The club's captain has been having treatment for sciatica, while the Portugal international underwent a nasal operation.
The manager told the club's official website: "Vidic is doing fine. He's on a course of injections to help his sciatica. If he improves then we'd consider bringing him out later on.
"The one thing we don't want to do is make it worse by flying him halfway around the world. So we have to consider that.
"Nani had an operation on his nose to clear a bit of breathing. At the moment we're not sure if flying is allowed so that's the one downside. We'll have to wait and see."
United face a Singha All-Star XI in Bangkok tomorrow in their first of five games in the Far East and Australia.