The Willie Mullins-trained Wicklow Brave won the Punchestown Champion Hurdle on his penultimate start before finishing fourth on his return to the Flat in the Belmont Gold Cup.
Frontiersman, trained by Charlie Appleby for Godolphin, ran a fantastic race to fill the runner-up spot behind Highland Reel in the Coronation Cup and would be a major contender if stepped up to a mile and three-quarters for the first time this weekend.
Frontiersman could be joined on the trip across the Irish Sea by the William Haggas-trained Dal Harraild, who was sixth in last Saturday's Hardwicke Stakes at Royal Ascot, as well as Ralph Beckett's Diamonds Pour Moi, Mick Channon's Elidor and Lord Yeats from Jedd O'Keeffe's Middleham stables.
Aidan O'Brien has won this Group Two prize in each of the last four seasons and could call upon Belgravia, Finn McCool and Wisconsin.
On the same afternoon Group Three honours are up for grabs in both the Finlay Volvo International Stakes and the Grangecon Stud Stakes.
The 10-furlong International Stakes has attracted 13 entries including last week's Queen Anne Stakes third Deauville and the long-absent The Grey Gatsby.
Sixteen juveniles are in the mix in the Grangecon Stud Stakes, with Fille Du Septembre, course winner Too Familiar and British hopeful Ellthea among them.
The main supporting race to the Irish Derby on Saturday is the GAIN Railway Stakes.
O'Brien has 12 victories to his name, with Ballydoyle aces like Rock Of Gibraltar, George Washington and Holy Roman Emperor all on the roll of honours.
His eight-strong team for this year's renewal includes last week's Coventry Stakes third Murillo and Norfolk Stakes winner Sioux Nation.
Jessica Harrington's beaten Coventry favourite Brother Bear and Fozzy Stack's runaway course and distance scorer Commander Grigio also feature.
