Ferguson was banned from the national team last year after a falling out with former manager George Burley however new boss Craig Levein has left the door open for his possible return.
“He will be a massive loss,” said Naismith. “We felt it at Rangers when he left here.
“It was a massive loss for us and it will be the same again for Scotland, especially on the international stage where you need players who have got a lot of experience.
“Fergie was the one who probably had the most experience out of the whole squad so it will be a big loss.
“But you just have to look at players in the past, guys like Paul Scholes and Ryan Giggs, who have prolonged their careers by stopping playing international football.
“So I can understand totally why Barry has done it.”
