Trainer Lorraine Erhart has swapped in-form jockey Larry Cassidy for star apprentice Luke Tarrant in a bid to complete a family double at Eagle Farm on Saturday.

The Erhart-trained Blue Mini scored an impressive win at the Sunshine Coast on Monday after a series of unlucky recent runs.

And stablemate and close relation Top Tone will be among the favourites for the CBS Air Conditioning Handicap (1600m).

Top Tone is Blue Mini's half-brother and Erhart would love to see their dam Gumball Rally recognised for having two winners in a week.

Blue Mini is by Antonius Pius while Top Tone is by Clang.

"We have a two-year-old who is a full-sister to Top Tone in the paddock. Unfortunately, she is the last of the offspring of Gumball Rally," Erhart said.

"When the filly was about five months old Gumball Rally had an accident and had to be put down."

Erhart, the wife of former Brisbane premiership-winning jockey Tony Erhart, is a widely respected horsewoman.

She has trained and bred horses for about 30 years and always had a good horse from a small stable with the best being the talented Selectaire.

Top Tone is typical of Erhart's horses because he has been consistent in winning two of his five starts as a two-year-old.

Cassidy had ridden Top Tone at all five of his race starts but Erhart felt there was a need to get some weight relief for the gelding with Tarrant earning a call-up with his 2kg claim to bring the gelding down to 57kg.