Tony McEvoy prepared Risen From Doubt to win at Flemington on Tuesday but the trainer was still pondering what might have been after Big Memory missed a Melbourne Cup start.

Big Memory was just outside the final field of 24 for Tuesday's Melbourne Cup after acceptances.

Two scratchings reduced the line up to 22 and McEvoy believes the time has come for the introduction of emergencies.

"What can you say? I hope something is done about it for people in the future," McEvoy said.

"I don't know how they do it. I'm an ex-shearer and a horse trainer so there's smarter people than me to work it out."

The Melbourne Cup is the only race in Australia with a 24-horse field and the issue of emergencies has been discussed in the past between racing bodies and the TAB.

However, the TAB would require a significant software upgrade to allow it to cater for more than 24 horses.

Risen From Doubt won the Maribyrnong Trial on debut at Flemington last year and scored for the first time since when he won a $100,000 support race on Tuesday.

He beat Rough Justice ($6.50) by a long head with 1-3/4-lengths to Alaska ($31) in third.

Risen From Doubt ($8) was given his chance in the Golden Slipper during the autumn but the colt was well beaten before undergoing throat surgery.

McEvoy said the colt was suited racing up the straight.

"He's two from two here. It suits his big action," McEvoy said.

"There's not much left for him now. I think we'll turn him out and bring him back in the autumn and target some sprint races."