Hand surgery has denied Robbie Henshaw first refusal on Brian O'Driscoll's Ireland berth after the Connacht centre was ruled out of next month's tour of Argentina.
The IRFU confirmed Henshaw exacerbated a hand problem in training this week, and will now miss the two-Test series against the Pumas.
The 20-year-old has been widely tipped to succeed the retired O’Driscoll in Ireland’s midfield, but will now miss out on the first chance to stake a claim for the vacant 13 shirt.
A statement from the Irish Rugby Football Union read: "Robbie sustained the injury earlier in the season and it had not limited his ability to train or play.
“He exacerbated the injury in training this week and further specialist advice has recommended that surgical repair of the damaged ligaments should not be delayed further.”
Ulster's Darren Cave will now be favourite to start at outside centre for Ireland's Tests against Argentina on June 7th in Resistencia and June 14th in Tucuman.
Ireland are yet to name a replacement for Henshaw, but losing the much-vaunted youngster will be a blow to head coach Joe Schmidt.
Former Leinster boss Schmidt will have viewed the summer tour as the ideal vehicle for blooding the next generation of centres as Ireland start the long build-up to the 2015 World Cup.
O’Driscoll retired from international rugby after his 141st Test match when Ireland edged out France in Paris to claim the RBS 6 Nations title.
The 35-year-old will bow out of professional rugby altogether in Saturday’s Pro12 final when Leinster take on Glasgow in Dublin.
O’Driscoll has tipped Henshaw and Cave to lead the charge to replace him for Ireland’s World Cup bid, but now Schmidt must do without his leading contender for the summer tour.
