Schmidt leaves door open to Zebo
Joe Schmidt has left the door open for Simon Zebo to return for the Six Nations.
"There's never actually been a rule, so the flexibility is always there," he said.
"My conversation with Simon was that, 'you keep playing and keep yourself in the right shape, and there's another squad to be named at the end of January that doesn't necessarily discount you'.
"The doors are more open than people think.
"But we've got a responsibility to the provinces that we take really seriously, and to the rugby public, to try to keep the people here as best we can."
For the first time, Schmidt explained the reason why Jonathan Sexton was the exception to an unwritten rule in 2013.
"I think at the time, I was new into the job," he said.
"To set a rugby team up in the space of a week is an incredibly difficult job.
"To have a thought process that is very similar to the guy (Sexton) that was running the team was, as much as anything, a real convenience to me going into a new job.
"That was a part of Johnny's selection," he said.
"He is also proven to be, over the last two Lions tours, the starting player in a Lions test match.
"Zebs has been great for us. But he hasn't reached the same level of selection, in those terms."
The Ireland coach argued against Wales' new rule, which permits players with 60 caps to move abroad and remain in Warren Gatland's plans.
"They're still leaking. Dan Biggar's gone to Northampton and Rhys Webb's gone to Toulon.
"There's their two pivots that have shifted out. That is the risk that you have.
"We're trying to minimise that risk."