Trainer Matt Cumani has two horses he knows will have no problems running out the VRC St Leger journey but has some lingering doubts whether they are mature enough at this stage of their careers.

Cumani will saddle Golden Authority and Marketplacer in the Listed race over 2800m at Flemington on Tuesday.

"It's a little bit of a throw at the stumps for me," Cumani said.

"I've got two horses that stay all day and a game owner.

"I've had this race on the radar for a while but their preps haven't gone as I expected.

"I thought they may have won a couple of times by now, but I've been aiming at this race so I thought we'd nominate and see what happens."

Cumani said while it sounded like he was talking down the ability of Golden Authority and Marketplacer he believed they had the potential to be good stayers as they get older.

"They're nice horses that haven't had the chance to shine yet," he said.

"I think the best will be seen of them when they're four or five-year-olds."

Cumani described Golden Authority as a big rangy three-year-old.

Golden Authority scored over 1600m on debut at Ballarat before running a last-start second over 2156m at Terang last month.

"He's been a little bit on the delicate side early so we've had to be a little careful with him and space his races out right," Cumani said.

He said Marketplacer was gelded after his first race start but was progressing well in his four starts this campaign.

Both Golden Authority and Marketplacer were bought at the Karaka Ready To Run sale for Gerry Ryan who had Melbourne Cup success with Americain in 2010.

Cumani said it was a great opportunity to be training two well-bred stayers for Ryan.

"Gerry loves Cup type horses and it's fantastic for me to be training for a guy like Gerry," Cumani said.

"To have two horses for him to run in a St Leger is absolutely fantastic."