California Chrome, runner-up in the Dubai World Cup last year, makes his eagerly-awaited reappearance in a dirt race a Meydan.
Unusually for a horse of his class he is running in a handicap, giving upwards of 10kg to his seven rivals in the dirt event on Thursday (Friday AEDT).
The 2014 Kentucky Derby and Preakness winner missed Royal Ascot in June when he picked up a foot abscess before the Prince of Wales's Stakes.
His future had been in some doubt but he returned to win at Santa Anita in January.
"He is a bigger and stronger horse this year," assistant trainer Alan Sherman said.
"He has done everything we have asked of him and we are very pleased with his preparations.
"We decided to run this week rather than on Super Saturday (March 5) to give him a month between races before the World Cup.
"We could not be happier with him and are really excited about having another crack at the Dubai World Cup."