YELLOWSTONE'S participation in the Emirates Melbourne Cup is in doubt after the four-year-old became cast in his box late on Monday.

His trainer Jane Chapple-Hyam said on Tuesday: "Yellowstone was rolling in his box and has picked up an injury. He has a gluteal muscle problem. You could see the scratches on the wall where he thrashed about.

"He's having physio and we're treating him with ice, but we probably won't know whether he will make the Cup until Wednesday or Thursday. We'll know more about the extent of the problem by then.

"Because the race is only a week away it means we cannot use any medication. He's been walking today and while what's happened is most unfortunate, we're not giving up on him running just yet."