The Thousand Guineas will always hold special significance for Steven Arnold.

And on Saturday the jockey has a golden opportunity to land a third success in the Group One fillies' feature after picking up the ride on leading contender Go Indy Go.

Arnold celebrated his first Group One win 14 years ago on All Time High for trainer Russell Cameron in the 1600m race at Caulfield.

"Then I won it again the following year on Magical Miss for Bart (Cummings) and she was a really good filly who went on to also win the Oaks," Arnold said.

"It's been pretty good to me. That's going back a while now though, so it would be nice to get another one on the board."

With Chad Schofield failing in his appeal to the Victorian Civil and Administrative Tribunal on Monday over an improper riding suspension, Arnold was confirmed as Go Indy Go's rider in Saturday's feature.

While Go Indy Go has been displaced as favourite by Lumosty, Arnold is convinced the Group One Champagne Stakes winner has the right credentials for the race.

"There's some nice fillies in the race but she looks the class filly," he said.

"Her win in Sydney was top quality. Her first run down here was ordinary but then she bounced back the other day and I thought her run was really good in the Prelude so she seems to be back on track.

"I've given her a couple of pieces of work this week and she's in good order and has got a bit of class.

"If she can bring that to the races on Saturday, I think she's the one to beat."

Arnold said Go Indy Go got lost in a solo course proper hitout out wide at Caulfield on Tuesday but was much sharper in her work on Thursday.

"I was really happy with her this morning," he said.

Go Indy Go won the Champagne Stakes (1600m) at Randwick in April with Schofield aboard but failed at Flemington first-up in the Danehill Stakes.

She showed she was back on target when she hit the line hard for third in the Thousand Guineas Prelude.

Lumosty has firmed from $5 to $4.40 since Tuesday's draw while Go Indy Go has eased from $4.40 to $4.80 with Prelude winner Afleet Esprit at $5.

While she is coming off a nine-length Sale maiden win last week, Lumosty's other three career starts have all yielded stakes placings including a narrow first-up defeat at the hands of Afleet Esprit at Flemington last month.