Mike de Kock believes York will bring the best out of Shea Shea when the South African sprinter goes for glory in the Nunthorpe Stakes at York on Friday.

The six-year-old has been out of luck in both the King's Stand Stakes and the July Cup since he took the Al Quoz Sprint at Meydan in March, but De Kock is optimistic the Group One tide will turn.

The trainer suffered the loss of the Arlington Million in Chicago on Saturday when The Apache was relegated to second on protest.

"I think it's the right course for him - flat and fast. I'm not so sure he's that effective over further than 1000 metres (five furlongs). He wants it fairly firm and fairly flat," De Kock told At The Races.

"He needs to get there late. Although he has won at five furlongs from start to finish it hasn't been at this sort of level. Certainly, we could do with change of luck altogether."

De Kock said he was quick to snap up Frankie Dettori for the ride once Christophe Soumillon lost his appeal against a riding ban which ruled him out of the Nunthorpe.

"Christophe got suspended for three days in France which he appealed against and lost. Frankie would be in the stands. He's won this race a few times, there was no hesitation (in booking him)," he said.

Soumillon also rode The Apache and De Kock said he was not surprised his horse lost the race.

"When I initially saw it on the internet and they showed the head-on I thought they would review the race," he said.

"There was one movement off the fence and then he kept on going, with his stick in the left hand. It definitely unbalances the other horse.

"If it happened to me I'd have felt aggrieved and it was very close to the line as well. For that reason I thought maybe they would overturn it."