John Gosden and Aidan O'Brien were interested observers of conditions at Churchill Downs on Thursday.
Plenty of rain has hit the Louisville circuit, where Gosden is set to saddle Prix de l’Arc de Triomphe heroine Enable in the Breeders’ Cup Turf and Roaring Lion in the Classic.
Gosden watched as Enable went out for exercise under Frankie Dettori, and said: "The condition of the course is sodden, and it's pretty loose on the top.
“I would say that on any other day’s racing here they wouldn’t be racing on the turf on Saturday. For all horses it will be a question of how they cope with it.”
However, the forecast is for the rain to die down on Friday and for Saturday to be dry.
That scenario heartens O’Brien, who expects the ground to quickly improve due to excellent drainage.
He said: “We’re pleased that the bulk of the rain came yesterday and today. I don’t think there will be as much tomorrow and it is forecast to be dry on Saturday.
“The turf course has an unbelievable drainage under it here, similar to the one at Adare Golf Club, and if any track will drain well, it’s this one.”
O’Brien’s 15-horse team cleared quarantine on Thursday morning and jogged around the main dirt track on their first visit in quite heavy rain.
“The horses have been in the barn the last few days and I couldn’t be happier with them,” said the Ballydoyle handler.
“They came out just now and trotted round once the opposite way, then turned round and did a gentle canter back to the winning post.”
Mendelssohn was among the squad as he prepares for the Classic and the chance to redeem himself for an unfortunate experience in the Kentucky Derby.
“Donnacha [O’Brien] rode him this morning and was pleased. He has a very good constitution, this horse, and Ryan [Moore] is looking forward to him. It will be interesting,” said O’Brien.
"The horse is by Scat Daddy, who himself is by Johannesburg [Juvenile Dirt winner in 2001], and Ryan is planning to talk to Jerry Bailey [Hall of Fame jockey] and come up with a plan, which we will leave to him.
“I’m pretty sure he will go forward and see how the race develops.”
