Confidence in Guelph's ability to handle a high-pressure Blue Diamond was the deciding factor in Kerrin McEvoy choosing to stick with her in Saturday's $1 million race.

Darley's No.1 jockey left his decision until the last minute but announced he would stay with the race favourite over stablemate Metastasio after Tuesday's barrier draw.

McEvoy, however, has sacked himself from future barrier draw duties after he drew barrier 13 for Guelph and then 12 for Metastasio in the field of 16.

Guelph eased from $2.90 to $3 with TAB fixed odds but held on to favouritism over unbeaten Adelaide filly Miracles Of Life who also drifted slighted from $3.20 to $3.40 after coming up with barrier one.

McEvoy said Guelph had always been his preference over Metastasio ($6.50) but he wanted to wait until after riding them in their final hitouts on Tuesday.

"Guelph is probably the filly that is going to improve the most and might end up the better filly, but there's not a heap between them," McEvoy said.

"Obviously there is question marks in a stronger-run race, how they handle the pressure and the tempo and also the step up to 1200 metres.

"Guelph is my pick on the basis that she's going to handle all those things a little bit better than Metastasio will."

McEvoy is chasing his third Blue Diamond after winning on True Jewels (2001) and star colt Sepoy (2011).

Trainer Peter Snowden was delighted with all three of his charges - Guelph, Metastasio and Montsegur (barrier eight) - after Tuesday's trackwork and maintained Guelph was his top pick.

But his confidence isn't as high as it was two years ago with Sepoy, who he felt was "home before he went out".

"Sepoy was an exceptional horse, I knew that after his second run," Snowden said.

"He was very, very good. I don't feel that with these three but I'm confident they all will run well."

Mark Kavanagh accepted with Saturday's Talindert Stakes winner Casquets but then scratched her almost immediately after she came up with the outside barrier.

Premier trainer Peter Moody has four starters with stable jockey Luke Nolen to ride Thermal Current who is on the fourth line of betting at $8.

McEvoy rates Miracles Of Life as the one to beat but believes it's an "open race".

"It looks like the fillies have it in their keeping. But it's going to be a good race," he said.