The Sydney Cup presents Brenton Avdulla with a rare chance to ride in a Group One race for Sydney's leading stable.

He will ride the Chris Waller-trained favourite Libran in the $2 million staying test at Randwick on Saturday.

Avdulla's first ride on Libran came when he finished third in a 1600m race at Randwick in February.

"I rode him first-up and I thought if he kept improving he could end up winning the Sydney Cup," Avdulla said.

Fast forward through the preparation and he has won three consecutive races at Listed, Group Three and Group Two level.

"For him to win his last three going into the Sydney Cup and go in as the favourite, it's pretty exciting," Avdulla said.

Libran leads the market as a $3.50 chance from stablemates Who Shot Thebarman at $3.80 and last year's winner Grand Marshal at $4.20.

Who Shot Thebarman will carry top weight of 57kg, Grand Marshal has 55kg and Libran is handicapped on 53kg.

Libran is coming off a last-start win in the 2600m Chairman's Handicap last Saturday.

It's a historically successful Sydney Cup path with seven of the past eight Sydney Cup winners coming from the race.

Three of those have completed the Chairman's-Sydney Cup double.

Avdulla believes Libran will have no issue getting the extra 600m required to win a Cup.

"I thought in his run on Saturday over 2600 metres his best work was late and through the post," Avdulla said.

"I thought once we get to the two miles he'll be OK."

If Libran is successful on Saturday he will be the fourth consecutive former northern hemisphere galloper to win the Sydney Cup.

"Hopefully he can get there in one piece and put his best foot forward.

"We'll see if that's good enough," Avdulla said.