Ireland defence coach Les Kiss admits "each hour matters" in the recovery of loosehead prop Cian Healy as he races to be fit for the Rugby World Cup.
The 27-year-old front-row, who is battling to recover from a neck injury ahead of Ireland's squad announcement, underwent surgery to correct the issue in May.
But with time running out, Kiss revealed it is a race against time for the prop.
"Cian is gradually being exposed to more and more rugby and he did a lot in the session today," the Ireland defence coach told Press Association Sport.
"I did some personal work with him at the end of the session around the contact area so some positive results are coming through there.
"As has been the case all the way along he'll get assessed this afternoon by the medics.
"Then we'll think forward from there about where he is going."
He added: "I'm not sure if we'd be able to say that's a chance of playing (against Wales).
"To tell you the truth today we did a bit of extra work in the contact area so he will be assessed by the medics again at the end of the session.
"We want to give Cian as much time as possible.
"It's funny because each hour matters for Cian at the moment and we've got people working on the rehab things.
"He did more in the session today which is promising but we need to get it from the medics on that one."