Ferguson opened the door to a return to the national team yesterday.
But McLeish said: "I don't know what the situation is with Barry. We will find out when and if he is asked the question by the next manager. He said 'Never again,' but we have seen Sean Connery say that in the James Bond films, haven't we when he made a comeback.
"Playing at international level and the Premier League is so demanding. If we get into a position where we get a strong squad then players will have to be aware of being rotated when internationals come around when tiredness comes in. He's been fantastic so far, but it's something he has to consider.
"I'm certainly not putting the block on him playing for Scotland but he's not 25 anymore.
"You look at the examples of Paul Scholes and Ryan Giggs. Maybe the fans don't want him back now, either. As far as I was aware the SFA have banned him, so if they have now reversed it, was it George's? That needs to be clarified. If it was the SFA, then if they have reversed it, it is up to the new manager, whoever that may be.
"George is out of the door and they are saying he can come back now, so like I say, the position needs to be clarified."