Trainer Tony McEvoy is weighing up the best option for Royal Symphony's final lead-up to his main spring target and is leaning towards the Caulfield Guineas Prelude.

Royal Symphony remained unbeaten when he overcame difficulties to storm home late and win the Listed Pin & Win Plate (1400m) at Flemington on Saturday at his first start of the season.

The Stutt Stakes (1600m) had been the race McEvoy had initially been looking at for Royal Symphony's Caulfield Guineas lead-up, but after monitoring the colt's recovery from Saturday, the trainer thought another run at 1400m might be a better option.

The Stutt Stakes is at Moonee Valley under lights on September 29 while the Guineas Prelude (1400m) is at Caulfield two days later and is 13 days before the Group One Caulfield Guineas (1600m).

McEvoy is convinced there is more improvement to come from the colt who made it four wins from as many starts when he came from what his trainer thought was a near impossible position at the 400m mark on Saturday to get home in the final strides.

"He had a really big blow yesterday," McEvoy told RSN927.

"He blew up in the body. And whilst we got the job done there yesterday, I thought he was closer to the mark than the way he recovered for me. So I think there's lots (of improvement) to come.

"There's two options. He certainly needs another race.

"The two races are the Stutt at the Valley or the Guineas Prelude.

"The way his condition was yesterday, I'm leaning to running him again at 1400 metres.

"I just don't think straight to a mile will help the Caulfield Guineas run, whereas another 1400 will really bring him up to where he needs to be for the final."

Royal Symphony is the $3 favourite for the Caulfield Guineas ahead of Merchant Navy at $6.