When Flemington trainer John Sadler was asked to take on an eight-year-old United States entire he was less than impressed.

Sadler could not really see the point in persisting with a relocated and ageing stayer.

Now, though, as he prepares Winchester for Saturday's $2.5 million Caulfield Cup, his view has changed radically.

"When we first heard that we were getting an eight-year-old stallion from America to train, naturally we weren't all that excited about him," Sadler said on radio RSN.

"We'd heard that he was a very good horse but when you think, he's eight, you think probably his best days are gone."

He is now decidedly upbeat about his veteran horse.

"He enjoys his work, he's got a beautiful temperament, he's been lovely and sound for us," Sadler said.

Sadler started getting interested when Jamie Mott, who will partner Winchester in the Caulfield Cup, spoke enthusiastically about him.

"Jamie Mott started spruiking him before I did," he said.

"He did a couple of pieces of work on good going and Jamie said he gave me a terrific feel."

Adding to his optimism is the fact that the Caulfield track is unlikely to disadvantage the horse on Saturday.

"The only negative about him is he's useless on a wet track. He won't go at all on a wet track so the firmer the ground for him the better."

Early trials were problematic but two ninth placings in the Group One Underwood Stakes (1800m) at Caulfield and the Group One Turnbull Stakes (2000) at Flemington were encouraging.

"Early on every time we tried him we kept running into a wet track and he didn't show us anything," Sadler said.

"But as soon as he got on top of the ground he went to the Underwood and we were delighted with him and we were happy with him again at Flemington in the Turnbull."

Sadler said the Caulfield Cup would be an extremely tactical race.

"I suppose the favourite (Glencadam Gold) is going to make his own luck, I imagine he's going to go forward along with a few others," he said.

"It might be a bit of a rush to that first turn but whether or not they put the brakes on then will be interesting.

"If they're any good, these horses, and they're ridden back and ridden quietly, they're going to reel off good sectionals so we're going have to try and expose him at some stage tomorrow and come into the race and hopefully we can figure."