Pony-sized sprinter Bulbasaur will boast a more robust appearance when he defends his unbeaten Caulfield record in Saturday's $100,000 Sir John Monash Stakes (1000m).

Trained by Charlie Goggin, the chestnut hasn't raced since Boxing Day when he won the Christmas Stakes at Caulfield "on three legs".

Missing the autumn carnival through injury was a bitter disappointment for connections but Bulbasaur, while not any bigger than 15 hands, has bulked up and is primed for his first weight-for-age assignment.

"He's come back a short, nuggety little sprinter whereas last time in he was probably a bit puny," stable foreman Tammy Mollross said.

"He has matured and filled out a lot and Charlie wants to get him out to 1400 metres this campaign and open up his options."

Despite his small frame, Bulbasaur has an imposing record of 12 wins from just 27 starts, including two Caulfield victories in his last four runs.

The gelding ran close to a course record when he beat the ill-fated Choreograph over 1100m in 1:2.52 at Caulfield on November 22.

A month later he raced with a collapsed near-side hoof in the home straight in the Christmas Stakes but was again too strong for Choreograph.

"After the race the wall of his foot had given way and he had been racing on the sole of his foot," Mollross said.

Bulbasaur has been in work for more than three months and the Monash has been his long-term first-up goal.

He confirmed he was on target for the feature last Friday when he scored an easy two-length win in a barrier trial at Cranbourne.

"It's a pretty classy field on Saturday and his first time at weight-for-age but I'm sure he will be pretty competitive," Mollross said.

"He's had two starts at Caulfield for two wins and we are hopeful he can make it three from three.

"Having a horse like him in the stable makes it easy to get out of bed in the morning."

Brett Prebble is having only his second ride on Bulbasaur after partnering him to a half-length second to Into The Night in the Hilton International Stakes (1100m) at Flemington during Melbourne Cup week.

AAP 2018 Published 22/07/04