Godolphin has been trying to win the Kentucky Derby since 1999, and Thunder Snow is Sheikh Mohammed's strongest chance yet, trainer Saeed bin Suroor says.

Saeed has sent seven of nine Godolphin contenders to the Derby but says he has "been waiting for this moment for a long time".

"Thunder Show is a tough horse with a lot of class, which you need because the Kentucky Derby is a very, very tough race," he said.

"He's the best horse we have ever sent (to the Derby)."

Thunder Snow has drawn barrier two for Saturday's race (Sunday AEST) time), meaning that jockey Christophe Soumillon will need to go forward from the start.

"Ideally, I would like him to take a good position, close to the pace and away from the kickback," Saeed said.

Thunder Snow touched down in the US on April 30 before testing the Churchill Downs track earlier this week.