|World Cup quarter-final: Ireland v Argentina|
|Venue: Millennium Stadium, Cardiff Date: Sunday 18 October Kick-off: 13:00 BST|
|Coverage: Live on BBC Radio 5 live and BBC Radio Ulster, plus live text commentary on BBC website|
Johnny Sexton will miss Ireland's World Cup quarter-final against Argentina because of a groin strain.
The 30-year-old fly-half had been named in Joe Schmidt's team on Friday but was withdrawn on Saturday morning with Ian Madigan taking his place.
Ireland's management reported that a further scan had shown a "very minor adductor strain".
Ulster fly-half Paddy Jackson comes into the match day squad, taking Madigan's place on the bench.
Sexton had been a fitness doubt after limping off with a groin injury during the first half of the Pool D win over France in Cardiff last weekend.
Iain Henderson comes into the second row to replace the injured Paul O'Connell, with Jordi Murphy and Chris Henry selected in the back row.
Sean O'Brien serves a ban while Peter O'Mahony has knee ligament damage.
Ireland coach Joe Schmidt resisted the temptation to include the versatile Henderson in the back row and play Donnacha Ryan at lock.
Ulster player Henderson partners Devin Toner, with O'Connell having been ruled out of the tournament after undergoing surgery on a badly damaged hamstring.
Henry starts in the number seven shirt after O'Brien was handed a one-week ban for punching Pascal Pape during the 24-9 victory over the French.
Blindside flanker Murphy occupies the place left vacant by O'Mahony, whose World Cup ended when he suffered a knee injury in the same game.
Prop Cian Healy is again preferred to Leinster team-mate Jack McGrath in the front row, while Ryan and Rhys Ruddock, who was called into the squad, are added to the replacements.
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Simon Zebo again misses out on a place in the squad while a decision on a replacement for another injury victim, Jared Payne, will be made on Monday.
The Irish, who will be captained by Jamie Heaslip, are bidding to reach the semi-finals for the first time.
Argentina were in the last four in 2007, having beaten Ireland along the way in the pool stage.
Suspended centre Marcelo Bosch is the only regular name missing from the Argentina line-up, having been banned for a week for committing a dangerous tackle against Namibia in Argentina's final pool game.
He is replaced by Matias Moroni, one of 10 changes made by Argentina coach Daniel Hourcade for the Ireland game.
Many of the leading players rested for the Pool C game against Namibia return, with scrum-half Martin Landajo starting ahead of Tomas Cubelli to win his 50th cap.
Ireland: Rob Kearney; Tommy Bowe, Keith Earls, Robbie Henshaw, Dave Kearney; Ian Madigan, Conor Murray; Cian Healy, Rory Best, Mike Ross; Devin Toner, Iain Henderson; Jordi Murphy, Chris Henry, Jamie Heaslip.
Replacements: Richardt Strauss, Jordi McGrath, Nathan White, Donnacha Ryan, Rhys Ruddock, Eoin Reddan, Paddy Jackson, Luke Fitzgerald.
Argentina: Joaquin Tuculet, Santiago Cordero, Matias Moroni, Juan Martin Hernandez, Juan Imhoff, Nicolas Sanchez, Martin Landajo; Leonardo Senatore, Juan Martin Fernandez Lobbe, Pablo Matera, Tomas Lavanini, Guido Petti, Ramiro Herrera, Agustin Creevy, Marcos Ayerza.
Replacements: Julian Montoya, Lucas Noguera, Juan Pablo Orlandi, Matias Alemanno, Facundo Isa, Tomas Cubelli, Jeronimo De La Fuente, Lucas Gonzalez Amorosino.