An already-strong police presence around the Melbourne Cup racing carnival has not been ramped up further after someone fired shots at the Racing Victoria chief steward's home.

Police say they are doing everything possible to ensure punters and racing staff are safe but will run the same security operation for the four race days as last year, with Australia's current terrorism threat level still at high.

Victoria Police Assistant Commissioner Stephen Leane says there will be a very visible police and security presence at Flemington, both on course and outside.

"The security environment unfortunately that we are in means that we do have to have our police in numbers and that will be the case this next four (race) days," Mr Leane told reporters at Flemington on Wednesday.

Mr Leane said police are working with the Victoria Racing Club to ensure the popular event is safe for all, as detectives investigate the Sunday night shooting at chief steward Terry Bailey's Templestowe home.

"We'll be making sure that we do everything to keep all our patrons and staff safe," he said.

"My crime command colleagues are working very hard to see if they can get a resolution to that issue."

Mr Leane said security arrangements for officials would be assessed again before Derby Day on Saturday but he would not provide any further detail.

"As we get closer to the event we'll make some assessments in regards to what needs to be done."

He would not comment on reports of possible bikie involvement in the incident at the Bailey home.

Racing Minister Martin Pakula has said security officers are now guarding the Bailey family.

Mr Bailey was getting on with his job on Wednesday, presiding over the barrier draw for the $1.5 million Victoria Derby.

The VRC has changed the way horses return to the mounting yard after 2014 Melbourne Cup runner Araldo was spooked by a flag being waved by a member of the public and broke his leg when he kicked out at a fence. He was put down.

VRC executive general manager Flemington, Mark Davies, said the horses could now return as soon as they finish the race, rather than sticking with the tradition of following a Group One winner down the pathway to the mounting yard.

Crowd numbers have been down for the Caulfield Cup and the Cox Plate at Moonee Valley but Mr Davies said Flemington ticket sales are up 10 per cent on the same time last year and crowds of more than 100,000 are expected for Derby Day and Tuesday's Melbourne Cup.