Aidan O'Brien was left scratching his head after his duo in the Betfred Dante Stakes at York trailed home a long way behind impressive winner Golden Horn.
O'Brien fielded both Ol' Man River and John F Kennedy but the pair were outpaced when the race began in earnest, finishing second to last and last of the seven runners respectively.
John F Kennedy had previously suffered a surprise defeat on his reappearance, while Ol' Man River had been last in the 2000 Guineas, where he was eased when his chance had gone.
O'Brien said: "We're disappointed. There's obviously something amiss with both of them at the moment.
"Ryan (Moore) said JFK travelled very well and then just cut out. He did that at Leopardstown and we put it down to the ground, but there's obviously something else.
"We cant find anything wrong with them at home. All the tests had been ticked off, so there'll be no Epsom for them. We will stop with them now and give them a break.
"As for what we will run in the Derby, we will see what happens in the next two weeks. Those three pulled a long way clear there and I would imagine that their trainers were very happy."
O'Brien completely ruled out any notion of 2000 Guineas winner Gleneagles stepping up in trip for the Derby, comparing him favourably with Giant's Causeway who notched a string of five Group One wins back in 2000.
He said: "There's no way Gleneagles will be going to Epsom. We haven't had a horse like him for a long time. He's an out-and-out miler but with more speed than Giant's Causeway."
Golden Horn was a thoroughly impressive winner, showing an excellent switch of gears to collar leader Elm Park, surging past Jack Hobbs in the process, with the trio pulling well clear of the rest.
Outsider Lord Ben Stack set the early gallop, with Elm Park racing keenly on his heels, but when push came to shove, Andrea Atzeni began to assert on the latter, winner of the Racing Post Trophy at Doncaster in October.
Jack Hobbs was primed to strike on his outside, while Golden Horn was tucked in on his heels, as Buick timed his run to perfection, scoring by two and three-quarter lengths.
The Anthony Oppenheimer-owned winner does not currently hold an engagement in the Investec Derby.
Gosden said: "It's very much up to Mr Oppenheimer (whether Golden Horn goes to Epsom). He's been very firm with me that he's a mile-and-a-quarter horse and he told me that all along, so we will see.
"The jockey felt he finished strongly today. He's a horse who has really come on since he won the Feilden Stakes. When he won the Feilden, we said we'd come to the Dante and that's what we've done.
"His work on Friday was superb. Coming up on the train today, I knew they could well be first and second but I half felt this guy is the professional at the moment. "