Monitor Closely has been added to the field for Saturday's Ladbrokes St Leger after trainer Peter Chapple-Hyam and owner Lawrie Inman gave the go-ahead.
It cost £45,000 to add the colt to the final Classic of the season, but a front-running victory under Jimmy Fortune in the Great Voltigeur Stakes at York persuaded the pair to take the plunge.
‘We have decided to supplement Monitor Closely for the St Leger,’ Chapple-Hyam said.
‘We were delighted by his win in the Voltigeur and feel it is worth a shot at the Leger.
‘His work since York has been good and we are just hoping the ground remains on the quick side at Doncaster.’
Monitor Closely is one of 10 confirmations in the final Classic of the season.
Aidan O'Brien is responsible for four with the well-fancied duo of Age Of Aquarius and Changingoftheguard, as well as Rockhampton and Von Jawlensky, still in the frame.
Godolphin are doubly-represented by Kite Wood, impressive winner of his last two starts, and Italian Derby winner Mastery.
Henry Cecil's Father Time, well behind Monitor Closely at York, and John Oxx's Mourayan, second to Profound Beauty last time, also stand their ground.
The Barry Hills-trained Above Average completes the field.
Jamie Spencer has come in for the ride on Father Time due to Eddie Ahern's suspension and told At The Races: ‘He's a good spare, I've sat on him a couple of times.
‘He's a horse that has a high cruising speed and he picks up. Mr Cecil felt the ground wasn't ideal for him at York last time. It was very firm the day Sea The Stars broke the track record, it was very quick and he felt it was too firm for him.
‘Hopefully we can get a decent racing surface.
‘On that one piece of form at Royal Ascot - which is way above all his other runs - if he can produce that, he should be bang there.
‘Obviously the Ballydoyle duo (Age Of Aquarius and Changingoftheguard) and Kite Wood will be the ones to beat.
‘Henry Cecil trains for a particular day and as important as York was, I'm sure next weekend is what he has been trained for and when I went to ride him, he pretty much said as much that the horse would improve from York to Doncaster, so let's hope he has.’
