Ireland start with James McClean as Wales put faith in Hal Robson-Kanu for Cardiff decider
Martin O'Neill has made three changes from the Ireland side that beat Moldova 2-0 on Friday as Robbie Brady, James McClean and Harry Arter are handed starts against Wales in their World Cup qualifying decider in Cardiff.
Welsh coach Chris Coleman has decided to hand a start to Hal-Robson Kanu after their 1-0 win in Georgia with Sam Vokes dropping out.
The home side are without the injured Gareth Bale with Ireland minus Shane Long who has a hip injury. Daryl Murphy leads the line for the visiting side after scoring twice in the victory over Moldova.
Wales are bidding to reach a World Cup for the first time since 1958.
"There is nothing for the players to fear," said Coleman. "I think both teams are going to go for it."
The winner of the match at the Cardiff City Stadium will be guaranteed a World Cup play-off spot from Group D, but there is an outside chance they could top the section if leaders Serbia fail to defeat Georgia at home.