Rugby World Cup: Iain Henderson handed start for crucial Ireland clash against Scotland in Paris

Leinster lock Ryan sustained a hand injury in his country’s 13-8 win over South Africa on September 23 and has been named on the bench, handing a first start of the tournament to Henderson.

Hooker Dan Sheehan has been preferred to Leinster team-mate Ronan Kelleher and will make his full World Cup debut in the other change to Andy Farrell’s starting XV, while back-rower Jack Conan is back on the bench following injury.

Sheehan came on against the Springboks a fortnight ago for his first appearance since suffering a foot injury in the warm-up win over England on August 19.

Number eight Conan is in line for his first outing since damaging foot ligaments two months ago.

Centre Robbie Henshaw, who has been struggling with a niggle, has been replaced on the bench by Stuart McCloskey, while flanker Peter O’Mahony will win his 100th Ireland cap.

Ireland will secure a place in the quarter-finals with a win or a draw, while defeat will leave them reliant on the scoreline and bonus points gained.

Veteran fly-half Johnny Sexton will captain his side for the fourth successive Pool B fixture following his return from an absence of almost six months due to injury and suspension.

The 38-year-old will be partnered by Jamison Gibson-Park, with the in-form Bundee Aki and Garry Ringrose in midfield and wings James Lowe and Mack Hansen joining full-back Hugo Keenan in the backline.

Sheehan will be sandwiched between provincial team-mates Andrew Porter and Tadhg Furlong, with Henderson packing down alongside Tadhg Beirne.

Centurion O’Mahony, who made his Test debut against Italy in 2012, will continue in the back row with world player of the year Josh van der Flier and Caelan Doris.

The Munster captain is set to become the 10th Irishman to reach the milestone, following Brian O’Driscoll, Ronan O’Gara, Rory Best, Paul O’Connell and John Hayes and current team-mates Cian Healy, Sexton, Conor Murray and Keith Earls.

Conan, Ryan and McCloskey are joined in reserve by hooker Kelleher, props Dave Kilcoyne and Finlay Bealham, scrum-half Murray and fly-half Jack Crowley.

Ireland team: H Keenan (Leinster); M Hansen (Connacht), G Ringrose (Leinster), B Aki (Connacht), J Lowe (Leinster); J Sexton (Leinster, capt), J Gibson-Park (Leinster); A Porter (Leinster), D Sheehan (Leinster), T Furlong (Leinster), T Beirne (Munster), I Henderson (Ulster), P O’Mahony (Munster), J van der Flier (Leinster), C Doris (Leinster).

Replacements: R Kelleher (Leinster), D Kilcoyne (Munster), F Bealham (Connacht), J Ryan (Leinster), J Conan (Leinster), C Murray (Munster), J Crowley (Munster), S McCloskey (Ulster).