The rain in Sydney has prompted Melbourne trainer Mike Moroney to add the Group One George Main Stakes at Randwick to the spring program of import Mr Marathon Man.

Moroney said Mr Marathon Man had experience winning in the right-handed direction in France and when a rain-affected track loomed for Saturday's weight-for-age George Main (1600m) it made the race an attractive option.

"We've always wanted to go there (to Sydney) but we only wanted to go there if it was going to be wet," Moroney said.

"It is going to be wet so we'll take our chance in what looks a pretty strong weight-for-age field, but on a heavy track it just might even itself out a bit more."

Mr Marathon Man was a Listed winner over 1800m on a wet track at Longchamp in April last year, one of four wins he recorded in France before joining the Moroney stable in Australia.

His only victory in six Australian starts came on a soft track at Sandown in June.

"We had a look at the weather forecast and it looked as if it would go our way," Moroney said.

"We're only guessing about him on the real heavy ground, but give in the ground is what he wants and it would take a few of the others out of the equation, I would think."

Mr Marathon Man finished fifth in the Group Two P B Lawrence (1400m) two starts ago before running 10th in the weight-for-age Group Two Feehan Stakes (1600m) at The Valley.

Moroney said jockey Damien Oliver gave the gelding a good report after the Feehan and believed he was up to that level.

Oliver is not riding this weekend because of a careless riding suspension and Moroney has booked Mark Zahra for Mr Marathon Man who is an outsider in the field headlined by favourite Avilius.

Randwick was rated a heavy (9) on Friday having received more than 80mm of rain since Monday.