Although Andy Farrell is expected to be able to call upon Johnny Sexton and Tadhg Furlong for the trip to Cardiff, the Ireland head coach is sweating over the availability of Henshaw, who remains sidelined with a wrist injury.
Henshaw has endured an injury-hit season, and while the centre is pushing hard to ensure he has recovered in time to face Wales, he has yet to fully overcome the issue.
Leinster, who confirmed that Sexton and Furlong are set to return ahead of the Six Nations, did not provide the same positive update on Henshaw.
“I don’t know, I don’t think he’s at the same position as Tadhg and Johnny is to be honest,” senior coach Stuart Lancaster said.
“(He’s) probably not our time-frame in terms of the next week for sure. He’s getting closer and closer.”
Sexton underwent an operation on his cheekbone last week, while Furlong had recovered from his ankle injury, only to suffer an unrelated calf problem in training. Both players will miss Saturday’s Champions Cup clash in Gloucester, as will Charlie Ngatai (hamstring), but Lancaster is optimistic Sexton will soon train.
“You’ve got to allow the bone to heal a bit,” he added. “You can’t do contact but equally, there’s always a risk and you don’t want to put him under that risk, certainly this week.
“But once the bone heals he should be able to get involved in training in a non-contact basis, but I don’t think it’s sensible to risk someone.”