Ireland has been dealt a big blow on the eve of their one-off Test against Australia, with experienced flanker David Wallace ruled out of the match through injury.
Wallace was put through a fitness test in Melbourne on Friday morning, but his injured calf showed signs of distress and he was immediately withdrawn from the team.
The inexperienced Shane Jennings has been called into the starting XV and will wear the number seven jersey, while Stephen Ferris will start on the bench.
Interim Ireland coach Michael Bradley said the loss of Wallace was a huge blow for the side, but he expects Jennings to step up and fill the void with ease.
"David has had a very good season with Munster and with Ireland. He played very well last week against the All Blacks so he will be missed," Bradley said.
"But Shane Jennings is a fine player and this creates an opportunity for him."
"Shane is a quality player and it will be a big test for him."
Ireland captain Brian O'Driscoll was bitterly disappointed at losing a player of Wallace's experience, but said there was enough quality in the side to cover for him.
"We are quietly confident that we will cause them a few problems," O'Driscoll said.
"We have got two very good playmakers in Ronan (O'Gara) and Paddy (Wallace) and hopefully they will be able to run a line or two."
While the battle in the halves will go a long way in deciding the winner of the clash, O'Driscoll believes Ireland needs to control the tempo up front if it is to come out victorious.
"Physicality is what wins games," O'Driscoll said.
"It's often talked about skill levels and tactics and everything, but if you win collision zones whether you have the ball or not, if you win more than 50 percent of them, you are off on the right foot."
"There have been games when we have played as considerable underdogs and we have just gone out and overpowered the opposition and I think if you need to do that every time you go out and play."
"It's a hell of a lot harder to defend than to attack and it starts from one to eight. Packs win games and if we win the game tomorrow I am sure it will be largely down to our front eight."
As head coach Stuart Lancaster polishes the axe he will soon wield over his World Cup training squad, Exeter Chiefs coach Rob Baxter has backed Jack Nowell, Henry Slade and Luke Cowan-Dickie to be given a stay of execution.
Italy Under-20s held off a late Samoa blitz to retain their place in the World Rugby U20 Championship on Saturday and head coach Alessandro Troncon believes the experience will have served as a valuable lesson for his young troops.