William Muir has called time on the racing career of Pyledriver after his horse of a lifetime suffered a setback ahead of an intended appearance at Kempton on Saturday.

A dual Group One winner having landed the 2021 Coronation Cup at Epsom and last year’s King George at Ascot, the six-year-old has suffered more than his fair share of injury problems during his career, but has nevertheless given his connections some fantastic days.

He proved the fire still burns bright when making a successful return from 11 months on the sidelines in the Hardwicke Stakes in June, his second Royal Ascot success after landing the King Edward VII Stakes three years ago, before finishing fifth in the defence of his King George crown in July.

The son of Harbour Watch was due to contest this weekend’s Unibet September Stakes ahead of a potential tilt at the Prix de l’Arc de Triomphe, but Muir, who trains in partnership with Chris Grassick, feels it is now right for Pyledriver to be retired.

“He worked on Saturday and to be honest he was sensational. He’s never a horse we’ve galloped off the bridle and done anything stupid with, but it was just the way he did it, the way he moved, the way he looked and he marched off the gallops like a lion,” said Muir.

“I actually said to the owners ‘you’ve just seen your next winner’ and he was fine 90 per cent of the way home, but when he got back to the yard he was just a little bit sore in the same place we first got the suspensory injury before.

“I called my vet and he said he’d just tweaked it and had a bit of inflammation round it and he was really sore to touch it, but like Pyledriver does on Sunday morning he was 100 per cent sound and bucking and kicking.

“We had him on the walker on Sunday and cantered him on Monday and the vet came back and looked at him and couldn’t believe it.

“We could run him on Saturday and he might win, but the horse has done so much for us and I just feel if I ran him and he tweaked it there’s a good chance he could do some damage, or like all of us if you’ve got a little niggle somewhere do you put more weight somewhere else and cause a problem?

“This horse has been fantastic to all of us, to the owners, to me, to the yard and to the jockeys that have ridden him and he doesn’t deserve anything to go wrong, so I think it’s the right time.

“He’s been a fantastic servant, but it isn’t just him. I’d be the same if this was a small-time runner at Southwell on a Saturday night. It’s just the case that I’m in this game because I love animals, I’ve worked with horses all my life and we’ve got to do what’s right.

“My mind and my heart is telling me it’s the right thing to do at this time.”