Leinster’s Jack Conan will make his debut for Ireland in Saturday’s World Cup warm-up against Scotland at Aviva Stadium in Dublin, while Sean O’Brien at number eight has been handed the captain’s armband.

Ian Madigan has his chance at fly-half, while wing Simon Zebo gets a run at full-back in his bid to convince head coach Joe Schmidt he is versatile enough to warrant a World Cup slot.

Scrum-half Isaac Boss, prop Dave Kilcoyne, lock Dan Tuohy and Conan are other Ireland squad men thrown the World Cup gauntlet by boss Schmidt.

Gordon D’Arcy, who last figured for Ireland in last November’s 26-23 victory over Australia, has also been handed a starting berth.

Ireland's regular captain Paul O'Connell takes a seat on the bench, primed for his first Test action of the new campaign in the long build-up to the World Cup battle. O'Brien becomes the 104th  man to lead the country.

Tighthead prop Mike Ross is the only player to retain his place from last weekend's 35-21 victory in Wales, the Leinster cornerstone again extending his record as the only man to feature in every Test of the Joe Schmidt era.

Tommy O'Donnell's World Cup-dashing hip dislocation against Wales might clear the back-row agenda somewhat, but 23-year-old Conan remains a long-shot for ultimate selection.

Ireland must name their final 31-man squad on 31 August, with Schmidt having started the culling process this week by releasing Rob Herring and Noel Reid.

O'Brien, Jamie Heaslip and Peter O'Mahony are nailed-on for final selection as Ireland's starting back-row, with Chris Henry and Jordi Murphy the likely additions.

That means Conan will need a debut to remember for all the right reasons to alter the thinking of Ireland's coaching staff at this stage.

New Zealand-born prop Michael Bent will win his fourth cap if called into action off the bench as expected.

The 29-year-old Leinster front-rower's ability to operate on both sides of the scrum puts him in pole position to claim the fifth and potentially final prop berth in Ireland's World Cup ranks.

Connacht's Nathan White will have something to say about that and will be itching for his Test debut off the bench.

The 33-year-old will become Ireland's third-oldest debutant of all time if he joins the fray on Saturday.

Ireland team to play Scotland in Dublin at 5pm on Saturday:
S Zebo (Munster); T Bowe (Ulster), J Payne (Ulster), G D'Arcy (Leinster), L Fitzgerald (Leinster); I Madigan, I Boss (both Leinster); D Kilcoyne (Munster), S Cronin, M Ross (both Leinster), D Tuohy (Ulster), D Toner, J Conan (both Leinster), C Henry (Ulster), S O'Brien (capt, Leinster)

Replacements: R Strauss, M Bent (both Leinster), N White (Connacht), P O'Connell (Munster), J Murphy, E Reddan (both Leinster), P Jackson (Ulster), D Kearney (Leinster)