They meet Australia in the last of their pool matches and still have a mathematical chance of making the semi-finals if other results go their way.
Ireland are seventh on the standings with four points after two games. The maximum they can reach is nine, the number which Australia and New Zealand currently have. South Africa top the standings on 10, along with England, and neither side can lose out to Ireland. France have six and Wales five points respectively.
Firstly, Ireland will need to beat Australia and score four tries doing it.
They will also have to win by 52 points to better their points difference over Australia. If they don't achieve that score but still win with a bonus point, then they must hope England beat New Zealand by a large score a highly unlikely scenario.
Also, South Africa must not slip up against France, which will allow the Tricolors a back door into the semis. Oh and Wales must not win, and if they do, at least not with a bonus point.
So the odds are heavily stacked against the men in green and a last four place is highly unlikely. But a win, however slender, against Australia would be a massive result in itself.
"We know that making the last four will be difficult but our focus has just been on winning this game against Australia," coach Pat Murray said.
"Australia play a very simple and effective game-plan, much like their senior team.
"We will have to try and stop them playing it and then see if they have a plan B."
Murray has resisted the temptation to make sweeping changes following the Ireland's 32-7 loss to South Africa in the second round of matches.
Wing Frank Daly comes in on the left for Eric Mahoney in a change to the 15 that bravely battled the Boks.
IRELAND U19 (v Australia U19): R Kearney (UCD) (Capt), F Daly (Thomond), F McFadden (Clongowes), D Cave (Sullivan Upper School), D Black (Portadown), E Ryan (UCC), M D'Arcy (Dublin University); C Black (Hartpury), G O'Meara (Lansdowne), K Griffin (Shannon), D McGowan (Buccanneers), F Walsh (UCC), D Laffan (Dublin University), B O'Mahony (Crescent College Comprehensive), D O'Reilly (Blackrock College). Replacements: C Muldoon (Galwegians), G Walsh (UL Bohemians), B Lynch (Rotherham Titans), A Saunderson (Ballyclare), G Cooney (Old Belvedere), K Lett (UCD), R Boles (Colstons Collegiate School), E Moloney (UCC), K Moloney (Blackrock College), E Toner (Lansdowne), D Dawson (Cooke).