His participation was temporarily put in jeopardy but he is now reported back on song.

"All is well and he is fighting fit and raring to go," Balding said today.

"It did upset his training regime and we had to jiggle a few things round but he worked on Monday and pleased his regular work rider, so we are all very happy.

"He had an eye infection and then he had a bout of colic so it hasn't been ideal but he's a pretty tough customer."

Phoenix Reach will be having his first race in Britain at the weekend since he was 10th of 11 behind Doyen in last year's King George.

However, he has since been campaigned overseas with great success and has recorded Group One victories in Hong Kong and Dubai.

"He was not right at all last summer and he bled after the race or during the race last year," Balding continued.

And of his chances on Saturday, the Kingsclere trainer added: "As ever it's a very tough race with Azamour, Grey Swallow and Eswarah as well - she's a potential star.

"But it would be foolish to underestimate his foreign form and he deserves to be there."

Australian ace Kerrin McEvoy is hoping Doyen can put recent disappointments behind him when he bids to repeat last year's brilliant victory.

Godolphin's son of Sadler's Wells has been unplaced on his three starts since thrashing a high-class field in the midsummer highlight at Ascot 12 months ago.

On his most recent outing the five-year-old could finish only fifth of six, beaten 14 lengths, behind Bandari in the Hardwicke Stakes at Royal Ascot at York.

McEvoy rode Doyen for the first time that day and was "disappointed" with the effort.

"He travelled well throughout the race but he didn't finish his race off. Under pressure he wanted to hang left and he didn't feel at home on the rough surface," McEvoy told At The Races.

"We go to Newbury where I'm hoping he can enjoy the surface, enjoy himself out there in the race and finish strongly.

"If he gets back to his best form I'm sure he'll have a great chance.

"Last year before his great wins he was working similarly to what he is now but last time he didn't show his true form on the track.

"If he can put that run behind him then I'm looking forward to Saturday."

Thierry Gillet and Pat Smullen are hoping for different conditions for their prospective rides in the £650,000 spectacular.

Gillet, who rides French hope Bago, would prefer for the ground at Newbury to be on the fast side while Smullen wants a bit more cut in the ground for last season's Irish Derby winner Grey Swallow.

The pair met in May's Tattersalls Gold Cup, where Grey Swallow prevailed by three-quarters of a length but Gillet hopes that his mount can reverse the form.

"We wouldn't want the ground to be too soft or holding," he told the Racing Post.

"The better the ground the better it is for us. It shouldn't be a worry as long as it's good or good to firm.

"There's no one particular danger as far as the competition is concerned, we'll have to watch out for everybody.

"But I feel fine, just perfect, and I'm very confident."

Bago was last seen finishing third in the Grand Prix de Saint-Cloud while Grey Swallow has not run since his victory at the Curragh.

Smullen said of Dermot Weld's grey: "Firm ground would be a concern. He doesn't need it soft but he wouldn't like it firm.

"I'm hoping for good ground, and if we get that it should be fine. If they don't get rain, I hope they'll water to prevent it being firm,

"It's going to be very tough as it looks like being a very hot race, but he worked well after racing at the Curragh and is in great shape."

Describing conditions at the track, clerk of the course Richard Osgood told At The Races: "At the moment we are still good to firm and we are putting a bit of water on it just to maintain it.

"We are concentrating in basically making it safe ground and my ambition is to make it good to firm ground with no jar."

King George VI And Queen Elizabeth Diamond Stakes betting:

Ladbrokes: 2-1 Azamour, 100-30 Grey Swallow, 6-1 Bago, Eswarah, 9-1 Ace, 10-1 Gamut, 12-1 Phoenix Reach, 16-1 Policy Maker, Yeats, 20-1 Doyen, 33-1 Mubtaker, 50-1 Norse Dancer, The Geezer, Warrsan, 66-1 Fight Your Corner, 100-1 Razkalla.

William Hill: 2-1 Azamour, 7-2 Grey Swallow, 5-1 Eswarah, 6-1 Bago, 10-1 Ace, Gamut, Phoenix Reach, 16-1 Yeats, 20-1 Doyen, Policy Maker, 25-1 Mubtaker, 50-1 Fight Your Corner, Norse Dancer, The Geezer, Warrsan, 66-1 Razkalla.