Kingston Hill could miss the rest of the season after suffering a further setback.

Trainer Roger Varian was forced to rule out the first half of the campaign after last year's St Leger hero suffered injury in the spring, but he had hoped to see him return this autumn before his latest issue.

Speaking on his website www.varianstable.com, the trainer said: "U nfortunately Kingston Hill has suffered a fresh training setback. He has sustained a soft tissue injury to his left fore."

He added: "He will again require a period of rest before he is able to resume training.

"Sadly, given the time of year this fresh setback will cast a doubt over whether he will be able to race this season."

As well as claiming Classic glory at Doncaster last September, Kingston Hill chased home Australia in the Derby at Epsom and finished fourth in the Prix de l'Arc de Triomphe during an excellent three-year-old season.