Trainer Adam Trinder does not want to see any more rain fall at The Valley ahead of the Cox Plate.

There was a thunderstorm in Melbourne on Friday morning while showers are forecast for The Valley on Saturday.

Trinder saddles $7 second favourite Mystic Journey in the $5 million Cox Plate (2040m) on Saturday and wants the track to remain in the good range.

But if a deluge does hit The Valley, Mystic Journey will still take her place with Trinder to rely on jockey Anthony Darmanin to find the best footing.

"She'll be all right up to a soft six, but anything worse than that, which I don't believe we'll get, she could potentially struggle," Trinder said.

"I wouldn't think we'd scratch, what we'd do is plot a path to find the firmest footing in that event, but I dare say she'll take her opportunity in the race."

After an awkward draw (8) when when fifth behind Kings Will Dream in the Turnbull Stakes at Flemington on October 5, Mystic Journey will start from six and come in one if third emergency Gailo Chop does not get a start.

Trinder expects Mystic Journey to be in the first half-dozen as the field passes the winning post on the first occasion.

Mystic Journey arrived in Melbourne on Friday morning and settled straight into familiar surroundings at Tony McEvoy's stable at Flemington without any fuss.

Trinder says Mystic Journey is fully accustomed to making the trip across Bass Strait, and does not turn a hair.

"She travelled over really well, she's settled in well, her weight is perfect and she's lovely and bright within herself," Trinder said.

"I'm really happy with how everything has transpired.

"I'm really proud of her. She owes us nothing and I feel she's racing in really good heart.

"Her Turnbull run was fantastic and she's done nothing wrong in our regard."

Mystic Journey won her first Group race at the corresponding meeting last year when she took out the Fillies Classic (1600m).

While confident Mystic Journey will give a good account of herself on Saturday, Trinder has a lot of respect for Japanese mare Lys Gracieux, the $3.50 Cox Plate favourite.

In his former life as a jumps jockey, Trinder rode in Japan and knows only too well how good the country's top horses are.

"I have an external understanding on the Japanese form as I rode over there in a previous career," Trinder said.

"I think their good horses are really good.

"I think their really good horses are exceptional and I think the mare (Lys Gracieux) may fall into that latter category."