He knows he is only warming the saddle for the suspended James McDonald, but Blake Shinn plans to make the most of his Group One chance on Contributer in the Caulfield Stakes.

The mount became available when McDonald was outed for careless riding at Randwick on Epsom Handicap day.

And Shinn, the regular rider of Pornichet, suddenly found himself free when Gai Waterhouse opted to replace him with Kerrin McEvoy in Saturday's Group One race.

It is all part of the swings and roundabouts of racing and given the Godolphin stable's domination of Sydney's biggest day of the spring at Randwick when they prepared five stakes winners, Shinn is looking forward to putting on the royal blue silks.

The jockey doesn't ride for John O'Shea often but they have history.

"I had a few winners for them last season, I won three or four races on Vashka so I've had a bit of luck with them," Shinn said.

Contributer was Sydney's weight-for-age star of the autumn but he has fallen from favour following two unplaced runs in Melbourne.

He is still being kept safe in the Caulfield Stakes market at $7 and O'Shea has previously stated the horse returned in burly condition and needed racing to get fit.

Shinn suspects a return to the distance over which he scored his most dominant Sydney autumn carnival win will also prove significant.

"He's building into fitness and getting up to 2000 metres will suit him," Shinn said.

"He won the Ranvet in brilliant fashion over the distance and he's drawn a great gate."

Meanwhile, McDonald has been confirmed as the new jockey for Terravista in the Manikato Stakes, replacing Hugh Bowman who will be serving a careless riding suspension.