But Dunn's second opinion on the group one is slightly more surprising because in a hotshot field he rates another stable runner Mataderos as the upset hope in the race.
Mataderos is a former Australian trotter who has never stopped improving since joining the Dunns and John says he will relish today's 3200m, even against his stablemate and other superstars like Muscle Mountain and Bolt For Brilliance.
"He has been beaten in his last two but both times he was coming back at the line," says Dunn of Mataderos, who will be driven by NZ Cup-winning reinsman Blair Orange.
"He is a better horse than many people realise and he begins quickly I can see him getting very hard and rolling on." That raises the possible scenario of Mataderos charging to the lead and handing that pacemaking role to Sundees Son so the lesser-fancied stablemate is worth adding in exotic bets.
But it is Sundees Son who is the apple of Dunn's eye and when he has been at his best in the last two seasons he has been all but unbeatable.
His crown of dominance has occasionally wobbled over the last 12 months either when the Dunns don't have him screwed down or one of those young guns in Muscle Mountain or Bolt For Brilliance can get in front of him.
Neither of those factors appear to be a danger today as Sundees Son has barrier three while Dunn says his beach work on Wednesday morning suggests he is bang on.
"He drove and trained beautifully and on that I'd say he is exactly where he needs to be," says Dunn.
"He is trotting squarely and feeling good which are always the best signs for him."
Sundees Son is unbeaten over 3200m, having won this race last year and the Rowe Cup twice so staying form simply doesn't get any better in this part of the world and he has so much respect it would seem any of the likely early leaders would be happy to take a trail on him.
For all the massive motors of Bolt For Brilliance and perhaps even more so Muscle Mountain they are going to need to be freakish to come around Sundees Son and beat him if he leads.
Punters worried about Sundees Son being drawn down low on the front line, a starting position rare for a horse who so often starts off handicaps, don't be: the last time he faces a similar situation was from barrier one in the Rowe Cup, he stepped beautifully, led and trotted his last 800m in 55.3 seconds to thrash Bolt For Brilliance.
If the great trotter is to take a misstep or race below his best, like stablemate Classie Brigade did in Tuesday's Cup, then Muscle Mountain shades Bolt For Brilliance as the most likely beneficiary.
He was stunning winning when sitting parked outside Majestic Man over a mile at Ashburton and after leading with the advantage of a handicap start over Sundees Son over 2600m last week.
But with that advantage reversed today his task is enormously more difficult and if Muscle Mountain can come around Sundees Son and beat him it really will signal a changing of the guard.
Bolt For Brilliance was far more like his old self when run down late by Oscar Bonavena in the NZ Free-For-All on Tuesday and is the other key contender.
