The path to the South Australian Derby has been a rough one for Gamblin' Guru but he has still managed to win two stakes races ahead of his home town Classic.

Trainer Leon Macdonald was busy saddling up his stablemate Go Indy Go for her Group One Champagne Stakes win in Sydney on Saturday and missed Gamblin' Guru's narrow win in the Chairman's Stakes (2000m) at Morphettville.

"When I got back I was told he was aggressive out of the gates and managed to pull the bit through his mouth," Macdonald said.

"He over-raced and pulled hard and had a bruised tongue afterwards so hopefully he can settle a bit better in the Derby."

Gamblin' Guru is on the third line of betting for Saturday's 2500m Group One with the Gai Waterhouse-trained VRC St Leger winner Order Of The Sun the favourite.

Rain is predicted in Adelaide this week and Macdonald is hoping the forecast is right.

Gamblin' Guru won the Geelong Classic on a heavy track in the spring, beating Tupac Amaru who ran second in the recent Australian Derby at Randwick.

The Adelaide gelding was being aimed at the Sydney Classic until he fell in a race at Morphettville on March 10. Stable jockey Clare Lindop broke a collar bone and 15 ribs in the incident with Jason Holder replacing her on many of the horses Macdonald trains in partnership with his son-in-law Andrew Gluyas.

The fall ruined Gamblin' Guru's chances of emulating his close relation, 1998 Australian Derby winner Gold Guru.

"He will be entered for the Queensland Derby but my gut feeling is he may have had enough after Saturday," Macdonald said.

"He has had to overcome the interruptions to his preparation and that might be asking too much of him."

Gamblin' Guru has had three starts since his fall, running second in a 1600m race before winning the Port Adelaide Guineas (1800m) and the Chairman's.