Dublin - Joe Schmidt has urged his Ireland rookies to seize their chance in South Africa after star fly-half Jonathan Sexton was ruled out Thursday of this month's three-Test series against the Springboks.
The Ireland coach confirmed that Sexton, 30, had undergone surgery that will sideline the playmaker for three months after suffering a shoulder injury in Leinster's 20-10 Celtic League final defeat by Irish provincial rivals Connacht at Murrayfield.
Luke Fitzgerald (knee ligament) and Dave Kearney (calf) also suffered injuries in the final which have scuppered their tour hopes, while Rob Kearney pulled up in training Wednesday with a hamstring problem and has been ruled out as well
Bordeaux Begles No.10 Ian Madigan steps in former Leinster team mate Sexton, while two of Connacht's Celtic League final try-scorers have also been brought into the Ireland squad.
Matt Healy replaces Fitzgerald, while full-back Tiernan O'Halloran comes in to round off a sparkling season with Pat Lam's side.
Ulster's Craig Gilroy is the other player to receive a late call up, but Schmidt insisted the disruption won't affect his expectations for the tour.
"Those three injuries came out of the Pro12 (Celtic League) final unfortunately," Schmidt told a news conference at Lansdowne Road on Thursday.
"Jonathan (Sexton) saw a specialist on Monday evening at 7pm (1800 GMT) and it was decided that the best course of action was to get surgery. All three of those players will hopefully be ready and fit for the start of the next season.
"Unfortunately those things happen, and it is disappointing, but it is a fantastic opportunity for some of those young players who come in and get their opportunity to put their best foot forward.
"It certainly doesn't change expectations and expectations are never based around results, as much as that's how we're judged. We can't control all the variables around the results."
The New Zealander added: "My expectation is that the players will work hard, they'll unite really effectively under (captain) Rory Best's leadership and that we will be competitive.
"Whether that's enough, we'll find out on the 11th, 18th and 25th of June (the dates for the three Tests)."
Schmidt admitted the loss of Sexton's experience and leadership qualities would hit his squad, but stressed those who were touring could still push for a first Irish win over the Springboks on South African soil.
"Look, I think for us if we can stay competitive we're always a chance," said Schmidt.
"If we can stay in the game for as long as possible I think that can potentially unsettle them (South Africa).
"The pressure does fall on them a little bit -- they're at home, they've never lost to Ireland at home."
Ireland will be up against a new South Africa coach in Allister Coetzee and Schmidt said: "I know that their motivation is going to be very, very high.
"When a new coach comes in some of the established players are going to want to demonstrate that they should have been there and deserve the right to remain there.
"There's going to be new players and the selection that Allister Coetzee has made is a real mix with some fantastic experience and, at the same time, some really exciting new players.
"Hopefully, if we can stay in contact with them for long enough in a game I think the players we have will potentially find a way (to win)."
Ireland start their series against South Africa in Cape Town on June 11 before facing the Springboks again in Johannesburg and Port Elizabeth on successive weekends.