O'Brien's bark could be made to add bite to the Wolfhounds

The measurables are what satisfy his always-on mind. The devil has been in the detail for the players working at impressing the national boss.

What cannot be accurately calculated is the 'added-value' Leinster's terrific two Sean O'Brien and Cian Healy can bring to this Six Nations and, more significantly, when they can bring it.

Of course, Schmidt will have his plan of where, when and for how long. What he cannot know is how their bodies will react to the body-shuddernig return to action.

It would seem O'Brien's rehabilitation from a shoulder operation has moved him ahead of Healy's from a severe hamstring tear in their race to return from injury.

"Sean trained fully on Tuesday, to be honest, so we'd be hopeful that he'd be involved in the first half of the Six Nations," revealed Schmidt.

The 27 year-old Carlow flanker won his 30th cap in November 2013 as his shoulder has taken him away from Ireland for 14 months.

It would seem likely that he would have to be named to play for the Irish Wolfhounds tomorrow to stand a chance of making the France match on St Valentine's Day or England on March 1st.

There is also the opportunity for Leinster A action next week or a Leinster PRO12 League match at home to The Dragons on February 15th.

The temptation to beef-up Ireland's campaign to retain the Six Nations has to be made in the shadow of the 2015 World Cup. The worth of O'Brien and Healy is simply too valuable to take a gamble on.

It does seem Healy has slowed somewhat in his repair, the hamstring being a tricky injury to overcome.

"We're still hopeful that Cian may have an involvement as well.

"Cian's just got to hit a few markers to finish off his full recovery because one thing we don't want to do is to have someone reinjure themselves and therefore put themselves out for an extended period of time."

There is positive feedback about the neck injury to scrum-half Conor Murray.

He was subject to the expertise of a specialist last week and is in line for another scan.

"Conor is feeling really good, we're quietly confident," reported Schmidt.

"He's got a few more things to tick off and he will be scanned again by the end of the week.

"If you get bruising, bruising causes swelling and swelling causes discomfort.

"That's a layman's view of what Conor has got presently, so we're hopeful that will dissipate, and has dissipated over a period of time since it first happened."

Schmidt is inclined to stick with what he has at the start of game week.

He doesn't like to introduce players in the middle of the build-up, although there are certain individuals for which allowances can be made.

Murray is one of them.

"By Monday, we'd like to have a clear picture so we can have uninterrupted preparation for Italy.

"We're hopeful he'll be okay."