Held-up after taking a trail, El Roca made late ground when fifth to Long John in the Guineas.
"He should have finished closer but he had no luck," Busuttin said.
Hugh Bowman has secured the Rosehill ride without committing to the horse for the carnival.
With Busuttin ruling out an Australian Guineas start, El Roca resumes in the Eskimo Prince in which he has drawn barrier five in a field of six, at the same 1200m distance he claimed a listed race in New Zealand before heading to Melbourne.
He goes to Rosehill after winning a barrier trial last week. "Opie Bosson rode him and was very happy so it's all go," Busuttin said.
Further south, Brenton Avdulla is eyeing his first Melbourne group one victory in the Lightning Stakes in what could be a big couple of weeks for the jockey.
Avdulla, who hails from Melbourne, partners one of the leading Lightning Stakes chances, Snitzerland, on Saturday at Flemington as he looks to add to the three group ones he has won in Sydney where he has been based in recent years.
Snitzerland has been close to group one success before and showed she was on target for the Lightning (1000m) with a sizzling barrier trial win at Rosehill last week.
The Gerald Ryan-trained speedster is just being shaded for favouritism in the Lightning by Samaready, while the following Saturday Avdulla is also set to partner Rubick in the Blue Diamond. AAP