The 2,000 Guineas hero Haafhd looks the pick of the runners in tomorrow's St James's Palace Stakes, though Johnston warns against underestimating Pearl Of Love.
"He is a seriously good horse on his day and will improve for his recent run in France," he said.
"Bandari has won three on the bounce and I'm leaning towards Wednesday's Prince of Wales's Stakes for him, while Royal Rebel has already won the Gold Cup twice and the mood I've got him in now I would not put it past him making it three."
Johnston welcomes the increasing international flavour at the Royal meeting, and the exploits of the star Australian sprinter Choisir have paved the way for raiders from around the world this week.
American sprinter Lydgate will carry Sheikh Mohammed's colours in tomorrow's King's Stand Stakes, while the same contest has also drawn a Hong Kong challenger in Cape Of Good Hope.
Tomorrow also sees another Hong Kong raider in Bowman's Crossing, who goes for the Queen Anne Stakes, while Ingrandire flies the flag for Japan when he tackles the champion stayer Mr Dinos and Royal Rebel in Thursday's Gold Cup.
The foreign influx adds a fascinating new dimension to the action on the track, but that isn't the only difference Ascot racegoers will notice. The inside of the course looks more like the surface of the moon than the lush green pasture which normally greets visitors to the Royal Enclosure.
A new track is being laid ahead of the £185million redevelopment programme which will shut the track for 20 months this autumn, but Ascot PR spokesman Nick Smith is confident the inconvenience will be kept to a minimum.
"I'm afraid there are a lot of clay foundations visible because of the relocation process, so people can expect the view to be different, but we'll dress it as best we can," he said. "But once people are at the races everything will be as normal."
And normal would do fine as far as Saeed Bin Suroor is concerned.
Godolphin's trainer has 20 Royal Ascot successes under his belt and, unlike Johnston, seems full of confidence after a series of near misses in the Classics this spring. He said: "Winning one race at Royal Ascot is never easy, but I feel we have one of our best teams for quite a while.
"Doyen in the Hardwicke Stakes, Papineau in the Gold Cup and Sulamani in the Prince of Wales's Stakes could be our three big chances.
"Sulamani looks much stronger and happier this year. Papineau has never run over the Gold Cup trip but has a lot of class, while Doyen was unlucky in the Coronation Cup at Epsom."
And what of Aidan O'Brien, who is undergoing one of the most torrid spells of his career after a series of Classic flops and the late withdrawal of Yeats from the Derby.
The Irish maestro will be under added pressure to deliver after drawing an Ascot blank in 2003, whereas Sir Michael Stoute and Kieren Fallon head to Berkshire on a roll following North Light's emphatic Derby success.
All the usual big names will be going at it hammer and tongs again, but on the eve of an event which combines the ancient and modern like no other spare a thought for Tim Martin.
The Sydney trainer hoped to see his £8m sprinter Exceed And Excel follow Choisir by landing Saturday's Golden Jubilee Stakes only to be thwarted when the colt developed a virus.
Martin will be on the plane home as the archetypal British summer Festival begins and admits to being "cheesed off" about missing it. "It's a bloody long way to come for a haircut," he said.
Horses to watch
Crimson Palace Tough and progressive Godolphin filly who goes for Wednesday's Windsor Forest Stakes
Powerscourt Under-rated Aidan O'Brien colt who could be the value in Wednesday's Prince of Wales's Stakes
Mr Dinos Romped home six lengths clear in last year's Gold Cup and set to take all the beating again on Thursday
