Gordon D'Arcy's departure for the World Cup in New Zealand has been delayed for 48 hours after the Ireland centre picked up a calf strain in training.
After a scan it was decided that the delay would minimise the possibility of swelling on the flight.
D'Arcy is now a doubt for the World Cup opener against the USA on 11 September.
Brian O'Driscoll has said that he is confident of facing the USA after missing Saturday's defeat by England because of a shoulder injury.
O'Driscoll was departing as scheduled for New Zealand with the Irish squad on Tuesday afternoon.
"Probably at a push I could have played in the English game but I think it was just smart to stay out of it," said O'Driscoll on Tuesday.
"Sometimes you have to balance a bit of match-fitness for weighing up against some knocks and some bumps and bruises that you have.
"I feel as though I should be grand in another two weeks and I should be in good shape to kick things off in the first game."
Saturday's defeat concluded a run of warm-up games which also saw Declan Kidney's side lose to Scotland and France (twice) but O'Driscoll remains upbeat.
"We have definitely got a lot more match fitness under our belt," added the Ireland captain.
"You would always have hoped for a win or two in those games, but we didn't get them.
"I think we have shown signs of some really good stuff at times but it is just that we have lacked that continuity."
Meanwhile, Ireland flanker David Wallace will be out for six months with the knee injury sustained in the World Cup warm-up defeat by England.
The 35-year-old Munster player is recovering from surgery to his right knee after he was stretchered off 21 minutes into the game in Dublin.
His Munster team-mate Felix Jones also faces a lengthy lay-off.
The full-back suffered ankle ligament damage in Ireland's World Cup warm-up loss to France earlier this month.
Jones will see a specialist next week to determine the length of his recovery.
Wallace's place in the Ireland squad for the World Cup has been filled by Leinster flanker Shane Jennings.
The World Cup was expected to be the international swansong for Wallace.