Midterm's participation in the Derby is in the balance after the colt was found to have suffered a setback following his run in the Betfred Dante Stakes at York.

The son of Galileo disappointed connections when fifth behind Wings Of Desire after being sent off favourite on the Knavesmire, but checks revealed the three-year-old, trained by Sir Michael Stoute, had a sore hamstring.

With the premier Classic at Epsom less then three weeks away, Midterm, who won the bet365 Classic Trial on his seasonal debut at Sandown last month, will have to make a speedy recovery to make the line-up.

"He's got a sore hamstring. Obviously, we're looking at that," said Teddy Grimthorpe, racing manager to owner Khalid Abdullah.

“We haven’t ruled out the Derby, but it’s an issue so we’ll see how it is and keep it monitored.

“No decision will be made until much later on.

“You want everything to go right before a big race, so it would have to go very smoothly from now on. Otherwise the horse is fine.

“It is not insurmountable or else we would have pulled the plug already.

“At least it gives us some explanation of why he was so disappointing. We have to wait quite a few days and like everything we have got to be sure, so it will be a last-minute decision.

“Firstly, he has to be sound and secondly he has got to please — which is slightly difficult as he is not a great worker so it is hard to gauge on how he is going.

“If he is lucky, he will become sound and do enough work to please Michael it is worthwhile going to Epsom. We don’t want to throw the Derby out because it is such an important race.

“Equally so, if Midterm does not come right in time, we would go the King Edward VII Stakes route.

“It was a bit mystifying at York because we were very hopeful of a big run. It could have been a lot worse than a hamstring in the whole scale of things. We have to wait and see.”