As a jockey James McDonald can't bet on horses, but he can back his own judgment.

He proved spot-on with his choice to ride Astern over Impending in the Run To The Rose at Rosehill.

One of four Godolphin runners the Group Two race, Astern ($6) toughed it out in a battle with the favourite Star Turn ($2.50) to win by a long head.

The stable jockey for the John O'Shea-trained team, McDonald said he had always had a fondness for Astern and the decision was not too difficult.

The colt has firmed from $26 to be the $4.60 favourite to win the Group One Golden Rose in two weeks, over 1400m, an extra 200m on Saturday's race.

"He's a very good horse and 1400 metres should no issue for him," McDonald said.

"I hope so anyway.

"He's a different animal compared to his two-year-old season and that's the only reason I went that way.

"I thought he was the real deal as a two-year-old. I think he is even more of the real deal now."

Tommy Berry, who rode the Hawkes Racing-trained Star Turn, said there were positives to take from his second.

"He got to the front too easy," he said.

"He pulled me there and he looked around a bit once he got there.

"We just needed something to take him a bit further into the race.

"I think he has still got improvement and 1400 metres won't be a problem."

Brenton Avdulla was equally buoyant about Impending ($8.50) who ran third, albeit 3-1/2 lengths behind Star Turn after getting squeezed mid-race.

"He ended up getting a good spot but just had horses all around him," Avdulla said.

"He didn't have much room till the 150 metres and worked to the line nicely.

"If I'd had the room earlier he might have finished 1-1/2 lengths closer."

Godolphin Australia's managing director Henry Plumptre said Astern and Impending were likely to be their only two Golden Rose runners.

"We'll wait and see but the other two (Tessara 7th and Telperion 11th) didn't go well enough to run in a Group One race in two weeks," he said.

Fourth-placed El Divino, a younger sibling of champion Winx, will still head to the Golden Rose with co-trainer Gai Waterhouse happy with his performance after he led to the turn.