Brian Meehan revealed David Junior to be "very fit and very well" ahead of the Coral-Eclipse at Sandown on Saturday.
Despite recent speculation about his well-being, the four-year-old is reported to have come out of his final piece of work on Thursday unscathed.
Last season's Champion Stakes winner will take on eight rivals in the Group One contest including Ouija Board, who put Meehan's colt firmly in his place in the Prince of Wales's Stakes.
David Junior finished two lengths in arrears of Ed Dunlop's classy mare at Royal Ascot but the Manton handler is confident that form can be reversed at the Esher venue.
Meehan said: "He did his final piece of work on Thursday morning and his regular rider was very happy with him.
"It is not long since Ascot but he looks really well and is happy with himself.
"Ascot was a bit of a muddling race and the mare swooped - she is a wonderful mare and to finish fourth to her isn't bad.
"It was disappointing not to win but when you look back to it, it wasn't a bad run to finish fourth to her and the form is there.
"It does look a good race with Ouija Board. Aussie Rules is well fancied, Sir Michael Stoute has two good chances (Notable Guest and Notnowcato) in there and Roger Charlton's horse (Blue Monday) is fancied too.
"Ouija Board has beaten us and now we have to beat her - that is the beauty of racing. We are not going to run and hide.
"He is very fit and very well."
In a surprise move earlier in the week, connections of David Junior purchased Eclipse contender Royal Alchemist from Mark Usher's yard in an effort to ensure a fast pace.
Royal Alchemist will run in the second colours of Roldvale Ltd and Gold Group International, a company owned by David Sullivan.
Sullivan paid an undisclosed sum to the Ridgeway Partnership for the filly, who made most of the running to take third behind Soviet Song in the Windsor Forest Stakes last time out.
"The mare is there too and she has a very good chance of running a nice race," added Meehan.
"If she helps the pace for David Junior then that is good for David Junior but she is there to run as well as she can - and she should go well."
Ed Dunlop has been delighted with Ouija Board's progress since her thrilling victory in the Prince of Wales's Stakes.
"It will be interesting to see how she gets on," the trainer told his website www.edunlop.com
"She seems very well and I've been very happy with how she came out of her race at Royal Ascot. She put all the weight back on very quickly that she lost.
"She is doing very well in this weather - she seems to love the heat. She thrives at this time of year, by the looks of it," he explained.
"The fact that she has been doing so well for so long is a total credit to the staff here at Gainsborough Stables. It's a big team effort.
"She did a routine piece of work last Monday and that went well. Touch wood, so far, there have been no hiccups going into the race."
While Royal Alchemist is set to ensure a proper gallop for stablemate David Junior, Dunlop feels the stronger pace will also suit his mare.
"More speed should suit our horse better. She stays well," he added.
Blue Monday is an interesting contender having been supplemented for the 10-furlong showpiece.
Roger Charlton's charge won last season's Cambridgeshire and has continued his progression this year, finishing a close fourth in the Wolferton Handicap at Royal Ascot last time.
His big-race jockey Steve Drowne has struck up a good partnership with the five-year-old and is looking forward to tomorrow's test.
"It will obviously be a tricky race with Ouija Board and David Junior but I think he has place chances and you never know - if we do get the heavy showers it will really help him," he said.
"It was a good run last time and the ground was probably just a bit quick for him down the hill and he wasn't enjoying himself, but when we hit the rising ground he stayed on well under a really big weight.
"He's come out of that race fine and I would say he does have good place chances," he reiterated.
David Elsworth's Snoqualmie Boy has also been supplemented for the contest having vindicated his handler's faith when landing the Hampton Court Stakes at Royal Ascot.
Big-race rider John Egan is under no illusions as to how strong tomorrow's field is, but feels the Montjeu colt should go well with conditions in his favour.
"I'm looking forward to it - he ran very well at Ascot and we're very happy with him," he said.
"He's improved and he's done well from his race, and 10 furlongs on good, quick ground is about perfect for him.
"It's a very competitive race but we bought our ticket and we're in with a shout."
Sir Michael Stoute will be represented by Notnowcato - who reopposes Ouija Board and David Junior - and Notable Guest, who has not been since finishing fifth in the Coronation Cup at Epsom.
Speaking of the latter, Lord Grimthorpe, racing manager to Juddmonte Farms said: "I spoke to Sir Michael Stoute yesterday and he says the horse is in good form.
"He blew him out on Wednesday morning and said he was very pleased with him and he's been pleased since - though obviously he has a bit to find to beat the top two.
"I don't think he handled Epsom as well as we hoped he might last time, but he has run nicely at Sandown before," he added.
Clive Brittain - successful with Pebbles in 1985 - will saddle Hattan in this year's renewal and is hoping for a bold show.
"Strictly on the form he doesn't look to have an outstanding chance but I have a great belief in this horse," Brittain told At The Races.
"I think this horse - if not going on to be as good as Warrsan - will certainly make his mark.
"I have no fears about running him in a Group One race as the other runners are there to be beaten - if nobody takes them on they never get beaten."
The nine-runner field is completed by Aidan O'Brien's French 2000 Guineas winner Aussie Rules.