Trainer John Thompson has used a tactic favoured by his old boss Bart Cummings in deciding to send Mamaragan to Melbourne for the Caulfield Guineas.

The colt is a dual acceptor for the Stan Fox Stakes in Sydney on Saturday, a race Thompson concedes looks a "perfect placement".

But after taking pause to consider what Cummings would do in the same situation, Thompson has opted to give Mamaragan a trip away with a long-term view towards helping the horse mature.

"I just went back to the Bart days and thought, what would he do?" Thompson said.

"He loved travelling horses like that. You can see a difference next preparation, more so than this prep.

"He does little things wrong in his races still. I know Sydney is easier this Saturday but I just think it's better for him long-term to have a trip and smarten him up a bit."

The Golden Slipper placegetter has had mixed form in Sydney this spring, resuming with a closing third to Anders in the San Domenico Stakes before he was run off his feet in The Run To The Rose.

Nothing went to plan in the Golden Rose after he over-reacted to an early nudge from jockey Nash Rawiller and went too keenly.

Michael Rodd will be instructed to ride Mamaragan quietly from a wide draw in the Guineas and Thompson has no doubt his colt is capable of featuring if he puts it all together.

"He's got the form around the favourites in the race so he's not far away if he gets it right," Thompson said.

"That's obviously going to be hard from a wide draw, first start around Caulfield but the favourites are in the same boat."

Mamaragan arrived in Melbourne on Thursday and was quoted at $34 for the Guineas with TAB fixed odds.

His withdrawal from the Stan Fox will cause a market reshuffle as he is a $4 second favourite for the Randwick race behind Peltzer.