Hopes of Aidan O'Brien's Kingsbarns making it to the Investec Derby at Epsom on 1 June appear to be receding.
The unbeaten colt went into winter quarters as favourite for the premier Classic after a smooth success in the Racing Post Trophy at Doncaster, where he beat subsequent 2000 Guineas third Van Der Neer.
He suffered a setback in March and the Ballydoyle trainer has been facing a race against time, conceding "he is probably not going to make it there".
Speaking at the Curragh, O'Brien said: "We are struggling and he's not going to be fit to run at Chester or Leopardstown. He's sound now, but he's done so little for so long he's like a sprinter.
"It's probably not fair on him, but we'll keep going and see. He's probably not going to make it there. For those races you have to have everything go smoothly.
"He's 20 kilos up on his racing weight. He's sound and is perfect, it's a pity but we will wait and see."
"He's probably not going to make it there" - Aidan O'Brien indicating would be geading for the Downs
O'Brien is set to have runners in the Classic trials this week, however, including Ballysax winner Battle Of Marengo.
He said: "The plan is for Battle Of Marengo plan to run in the Derrinstown (at Leopardstown on Sunday).
"Magician could go for the Dee Stakes (at Chester on Friday) and Ruler Of The World is a possible for the Vase (Chester, Thursday).
"We'll split them up a bit."
He added: "We might run Imperial Monarch in the Ormonde Stakes (Friday) and Nevis might go to Lingfield on Saturday (Lingfield Derby Trial)."
O'Brien's Newmarket 2000 Guineas runners could go for the Irish equivalent, while 1000 Guineas third Moth has the Irish 1000 as an option.
O'Brien said: "She is in the Oaks too but we often run them in the two races. She was very green at Newmarket, swapping and changing her legs."