Horse Talk with Simon Jackson:

Top horse-racing tips and the latest news.

AIDAN O’Brien is eager to run Cazoo Derby co-favourite High Definition before Epsom following news he will miss the Novibet Derby Trial Stakes at Lingfield on Saturday.

O’Brien revealed the son of Galileo, who is now 5-1 co-favourite for the Derby alongside stablemate Bolshoi Ballet and the William Haggas-trained Mohaafeth, will not run due to unsatisfactory blood results.

High Definition won both starts last year but has not run since winning a Group 2 at the Curragh last September and O’Brien has not ruled out the Dante Stakes at York next week.

“His blood count didn’t come back proper – his SAA (Serum Amyloid A) was very high and that is usually an indication of inflammation or infection somewhere, but we couldn’t find either anywhere in his body.” O’Brien said.

“He scoped perfect this morning (Thursday). Maybe it was just one of those things, but we’ll do his bloods every day going forward and see.

“He’s in the Dante and we’ll see what happens over the next few days,” the trainer told Sky Sports Racing.

“When that (SAA) marker was high, we wouldn’t usually run with it and we just didn’t want to take a chance.

“It’s a bit of a pity because we were looking forward to it (Lingfield) and the timing and everything was good.

“The Derby has always been his plan and it would be very hard to go into the Derby without a run.

“For us, we need to be getting out, because with the travelling you’d like a bit of time between their first and their second run.

“Hopefully it might come together in the next few days and we’ll be able to start somewhere.”

Horse Talk with Simon Jackson. Showcasing horse racing in London and the south east.