Alan Gaffney believes that Jonathan Sexton's move to Parisian club Racing Metro could have a serious impact on his performances for Ireland.
"Johnny brings so much to Ireland. They're going to have nearly no control over what he does in France," he said.
"The French don't care. The French will keep using Johnny up and playing him and playing him.
"Whether he's got injuries or not, there won't be any rest periods. They'll just keep playing him and they'll get their value.
"And how that's going to impact on Ireland we'll see. Ireland does not have a number 10 anywhere near the level of Johnny right now.
"I just don't see how they've allowed him out of the country."
Gaffney said he was surprised to hear the news that Ronan O'Gara would follow Sexton to France as a kicking coach at Racing Metro.
"I wouldn't expect that anyone consulted Johnny before the decision was made," Gaffney laughed.
"I would find it really amazing if Johnny was going to take advice from Ronan on how to kick goals.
"Don't get me wrong, Ronan has been one of the best kickers the world has ever seen. But Johnny is a great goal kicker in his own right."
Gaffney added that he is "interested" to see how O'Gara's move works out.
"One thing he's (Ronan) got to learn is being able to work with people and I'm saying that in a nice way," said Gaffney.
"But Ronan is a very, very strong-minded person and if players treat Ronan like he treated coaches at various times he's not going to like it. He's not going to like it at all.
"Ronan's coaching days will be interesting. I'd like to be a fly on the wall in the early parts of Ronan's coaching career. I think he can be successful at it, I really do, but it's going to be interesting."