Canada will provide the opposition for Ireland's opening game in Pool D, with head coach Joe Schmidt naming an attack-minded backline for the match.
Fit-again Cian Healy will start from the bench as he looks to try and regain his place in the side ahead of the bigger pool matches to come.
Healy's Leinster team-mate Jack McGrath is currently in possession of the jersey and he believes that their competition for the position is getting the best out of both of them.
Nenagh's Donnacha Ryan is among the replacements for todays game.
Kick-off at the Millennium Stadium this afternoon is at half-past two, while the late match in Pool D will feature top-seeds France against Italy in Twickenham at 8pm.
Elsewhere today South Africa will begin their campaign when they face Japan in Pool B from 4:45 while the opening game of the day is in Pool C, where Tonga and Georgia go head to head in Kingsholm at midday.
England top Group A after a 35-11 bonus point win over Fiji at Twickenham last night.
