A disappointed Desleigh Forster has pulled the pin on an Australian Derby start for Group One placegetter I'm Belucci.

Second to Vanbrugh in the Spring Champion Stakes in October, I'm Belucci weakened after leading to finish last in Saturday's Rosehill Guineas won by Tarzino.

His trainer has taken him home to Brisbane where he is entered in Saturday's Jim Beam 3YO Hcp (2020m) at Doomben.

Forster will wait until as late as possible to commit the colt to a start.

"Glen Boss elected to lead in the race when there was no pace," Forster said.

"I know he led in 1600 metre race in Brisbane but it was never going to work in a 2000 metre race.

"I had his blood tested on Wednesday and we will monitor him over the next few days.

"You wouldn't know he had been away. The trip to Sydney is so quick these days.

"But we will wait to see how he is late in the week before making a final decision."

She has booked in-form apprentice Luke Dittman for I'm Belucci and he will reduce the gelding's top weight to 57.5 kg.

"Luke will be riding him back in the field and we will see what he can do from there," Forster said.