Aidan O’Brien felt the sloppy dirt conditions in the Kentucky Derby at Churchill Downs were against Mendelssohn.
The UAE Derby winner was attempting to become the first European horse to win the Classic but torrential rain made the surface atrocious.
After receiving a hefty bump coming out of the stalls Mendelssohn and Ryan Moore were always on the back foot and he eventually trailed home in last.
“We learned a lot, we prepared for normal dirt racing,” O’Brien told ITV Racing.
“Everyone was of the opinion that if you didn’t get a good start your race is over in those conditions..
“Because of the bad kickback when it rains it is demoralising for a horse.
“American horses would have trained on it before but Ryan even said when he cantered to the start he was uncomfortable because it was coming up underneath him. It was a total extreme and we weren’t prepared for that.
“If we were in that situation again we might be a little more prepared.
“I think we are thinking of the (Breeders’ Cup Classic) so it looks like a break now before two preps, wherever they may be, and then hopefully back for the Classic.”