Estimate extinguished a 15-month drought with her victory in the Doncaster Cup, but question marks still hover around her making a play on the Melbourne Cup.

While Estimate, raced by Her Majesty The Queen, always seemed to have the Group 2 race in her grasp, trainer Sir Michael Stoute and the Queen’s racing manager John Warren were non committal about the mare making the trip to Melbourne.

Warren was the more candid of the pair after Estimate, the $2.20 favourite, scored by one and a quarter lengths from Whiplash Willie with a neck to Kalann, $81.

"There are only three options - Ascot (Champions Day), Paris (Prix du Cadran at Longchamp) and Melbourne. My hunch is she probably won't go to Australia,” Warren told the Sporting Life.

"Ascot could be favourite in the sense that the Queen could see her race again, but Ascot is two miles, whereas the French race is further.”

Warren also cited concern about Estimate travelling, the likely ground at Flemington and the Cup being "a bit stop-start”.

"Obviously the travelling is a huge ask as well, so there are many complexities,” he said.

"The tempo of the race in Australia is not quite what this filly is about. This filly is about sticking it out and Australia can be a bit stop-start.

"I know there's been huge pressure from the Australians for the Queen to have a runner, understandably, which would be amazing to do and, for so many reasons, it's good.”

Stoute also aired his concerns about a possible firm track at Flemington.

"You'd wonder a bit about the ground at Flemington as she does like a little bit of forgiveness in it,” Stoute told the Sporting Life.

"We'll think about it and discuss it with the Queen and John Warren."

Warren also had reservations about sending Estimate across to Australia with a view to her pending breeding career.

"I sound as though I'm talking myself out of the Melbourne Cup, but there are a number of people that will have an input,” he said.

"We'll stick all the heads together, put a proposition to the Queen and see which way she feels it will go forward."