Garry Ringrose trained with Leinster rather than Ireland after being drafted into Joe Schmidt's squad, although the centre has been backed to make a Six Nations impact after recovering from an ankle injury.
Centre Ringrose was among three players drafted in by Schmidt to cover injuries, with Robbie Henshaw's absence a key concern ahead of Saturday's clash with Wales at the Aviva Stadium.
Chris Farrell is expected to get the nod in midfield, but Ringrose was reported to have departed for Ireland's base after taking part in a more rigorous training session with his club side to begin the week.
"I personally think it's a push," Leinster scrum coach John Fogarty told reporters, when asked if Ringrose could make the XV.
"But that's my opinion on it. How long has Garry been out? Six weeks. I think it's a tough one but on the other side of it, he's so intelligent. If he's physically really, really good, he's probably one of the only guys you could move back in there.
"There is much instinct that is sharpened through game time, so that's why I'm saying that these lads can sharpen themselves over one or two games. Some of them get back so quick, but sometimes they need that game for their own confidence. I'm not saying this is the case, it's just my opinion on it.
"I think he is smart enough to move straight back in. He's physically going to be in a good position. It's a big call. Joe has made great calls over the years, so if Joe puts him on the bench..."