"He's very well in himself," Lees said. "We've always been pretty open that we're guarded about him over the shorter trip but all the natural things, the extra 200m, the bigger track and genuine tempo are all things that are going to suit him.
"It's just whether he can react at the 2000m."
Happy Trails has displaced Protectionist at the top of betting, firming from $6.50 to $4.80 since Tuesday.
Protectionist has eased from $4.80 to $5.
Peter Young Stakes winner Mourinho is in career-best form and is at $9 along with Spillway.
Protectionist's Melbourne Cup win was one of the easiest of the modern era when he scored by four lengths over Red Cadeaux, a rival today.
Happy Trails will be chasing his fourth group one win at the track, having won the 2012 Emirates Stakes, the 2013 Turnbull Stakes and last year's Mackinnon Stakes.
The Chris Waller-trained Foreteller is also a group one winner at the track in the 2013 Makybe Diva Stakes.
Sydney horseman John Hawkes rates Chautauqua as his best chance for an overdue win in the Newmarket Handicap at Flemington today.
"We haven't been lucky enough to win this one, not that we've had a lot of runners, but certainly it would be nice to win," Hawkes said.
Chautauqua is one of the favourites for the race, promoted as a showdown between the Hawkes Racing star, Sydney sprinter Terravista and last year's winner Lankan Rupee.
Lankan Rupee has 3kg more than Chautauqua and 2kg more than Terravista on their Darley clash.
Lankan Rupee has joined Chautauqua at the top of betting at $3 with Terravista and the 3-year-old Brazen Beau at $5. Terravista will attempt to become the first horse since Polycrates in 1917 to win the Newmarket first-up.
Superstar jockey Joao Moreira needed little convincing to make the trip to Flemington to ride Brazen Beau against the world's best sprinters in the Newmarket Handicap. The tearaway leader in the Hong Kong jockeys' premiership is unbeaten in two rides on the Chris Waller-trained colt, highlighted by the group one Coolmore Stud Stakes at Flemington last spring.
"I have a very good memory of the last times I've been to Australia and hopefully I can keep on having those good memories," Moreira said.
He was sure Brazen Beau had the improvement to make a race of it, especially with 6.5kg less.
With Moreira flying in from Hong Kong, Singapore-based Craig Newitt will also jet in for his ride on Lankan Rupee in what could be another international finish to a group one race in Melbourne.
Hong Kong-based Brett Prebble and Douglas Whyte provided the quinella with Wandjina and Alpine Eagle in the Australian Guineas last week. AAP
