Leo Cullen rates Leinster captain Jamie Heaslip as no better than "50-50" to make The Champions Cup clash with Castres at The RDS next Saturday.
"Jamie didn't do any rugby last week. He's just making sure he gets himself ready so that he can start pushing again.
He's pretty close. We'll see what he looks like training today. He's probably 50-50- for the weekend," said the forwards coach.
"He had a pretty significant trauma to his AC. He generally recovers pretty quickly.
"But, it's how he manages the week and what it's like and we can test him out with contact and make a decision on him later in the week."
The possibility of being without the omnipresent number eight is not quite the catastrophe it would have been last season given the genuine emergence of Jack Conan in the last two months as an alternative.
However, the bank of experience earned by Heaslip and his all-round competency in all aspects of the game would make him a major loss to the province.
The Ireland mainstay is not the only doubt with Leinster set to make a decision on an appeal of Jack McGrath's three-week suspension sometime before the Wednesday deadline.
The management were known to be dissatisfied with the consistency of a decision making process that enabled citing commissioner Eugene Ryan to put McGrath in the dock and alleviate Roger Wilson of any case to answer for a stamp on McGrath.
In the original judgement, the Independent Disciplinary Committee viewed McGrath's transgression of the rules as a mid-range offence worthy of a five-week suspension.
This ruling was reduced to three weeks on the basis of McGrath's clean disciplinary record and on his conduct at the hearing.
"We got the judgement on Friday. We've got until Wednesday to lodge an appeal, if that is deemed the correct course of action," said Cullen.
At present, McGrath is scheduled to miss out on Leinster's vital Champions Cup Pool Two clashes at home to Castres Olympique this Saturday and away to Wasps at The Ricoh Arena in Coventry on Saturday week.
The best guesstimate for Leinster would be that the ban be diminished from mid-range to lower-end, in other words five to two weeks with one week off for good behaviour.
This would leave the Cardiff Blues PRO12 League match last Saturday to stand alone as time served and release McGrath back to Leinster for the European Cup matches.
It would seem likely Leinster will decide to test the suspension in light of the rehabilitation of Cian Healy.
"We do need him, yeah for sure," added Cullen about McGrath.
"You need all your best players available. With injuries and this unfortunate suspension, we just have to manage the bodies that we have."
Cullen also sought to clear up any confusion over the miracle recovery powers of Healy and Sean O'Brien.
"When you have those long-term injuries, you have some really good weeks and, maybe, weeks where they struggle and don't make any progress and, sometimes, go backwards.
"They're probably still a little bit off. They still have a fair few boxes to be ticked with the two of them. They're getting closer," he said.
"You almost want to protect them from themselves.
"Those two guys are so keen to be involved. It's about letting the medics use their experience.
"In terms of Cian's situation, he is quite similar to Straussy.
"Richardt came back from a hamstring tear off the bone as well, so they have a pretty good idea, dealing with the surgeons as well outside of this environment.
"Sean coming back from his shoulder, there is very set return protocols with him. It is taking all those things into consideration. The medics will be the ones that will ultimately decide."
Cullen was not certain about the prospects of wings Zane Kirchner (leg) and Fergus McFadden (head) as the countdown for Europe behind in earnest again.