Chad Schofield played his part in a Cox Plate upset last year and the young jockey is convinced he can do it again.

The Godolphin colt Sweynesse has been included at the club's discretion in the capacity 14-horse field for Saturday's $3 million weight-for-age race, paving the way for Schofield to get a chance to back up his win on Shamus Award.

Schofield guided three-year-old Shamus Award to a memorable all-the-way win in last year's Cox Plate to notch his first Group One triumph.

After riding Sweynesse at Moonee Valley's trackwork session on Tuesday, Schofield was glowing in his praise of the colt.

"He gave me a magic feel and gee I hope he gets in," Schofield said.

An hour later, the jockey's hopes were realised when the Moonee Valley Racing Club committee accepted the John O'Shea-trained colt into the star-studded field.

He is one of three three-year-olds in the race to carry 49.5kg along with the Gai Waterhouse-trained pair Almalad and Wandjina.

"Last year I went into the race on a maidener. This year I'm going in with a horse that's won four from five. So I'm a chance," Schofield said.

Sweynesse, however, has to overcome barrier 12.

The colt won the Group Three Spring Stakes and Group Two Gloaming this spring before being beaten for the first time when third in the Group One Spring Champion Stakes.

Sweynesse worked with stablemate Gouldian on Tuesday and Schofield said he took everything in his stride and handled the Moonee Valley circuit well.

"He's just the whole package. He's got attitude, physique, substance and style. He's got it all," Schofield said.

The 20-year-old has had an interrupted season. He missed the first few weeks as he completed his recovery from a neck injury suffered in a race fall in June, then served two lengthy suspensions, the latest a month-long ban for improper riding.

Schofield says riding on Cox Plate day in front of a big crowd is something special because of the amphitheatre that is the Moonee Valley racecourse.

"To come in on Saturday with a chance to defend the Cox Plate would be pretty good," he said.