Early season form in Ireland will determine the strength and number of horses six-time Melbourne Cup winning owner Lloyd Williams has in Victoria for the spring.

Williams' son Nick said the ownership group could have four or five of their Irish-trained horses in Melbourne for spring assignments joining their local team prepared by Danny O'Brien and Anthony Freedman.

Rekindling, trained by Joseph O'Brien, was Team Williams latest Melbourne Cup winner in 2017.

O'Brien has a number of the Williams-owned horses about to kick off their campaigns in Ireland in coming weeks, with some well known to Australian punters including Yucatan, Master Of Reality and Latrobe.

Others including Buckhurst, Pondus and Degraves, have been earmarked as potential Melbourne spring horses.

With racing having recently returned in Ireland, Williams said form, and injuries, would determine the make up of the team.

"It's been a difficult season they've had," Williams told RSN.

"They're just starting off now so the races are all a bit crowded together.

"It's an interesting time there and it will probably take a month or so to sort the form out and work out where we're going."

If the horses make it to Australia, who will be training them is still to be finalised.

While horses are able to enter Australia, most people travelling from overseas are currently unable to do so.

"Racing Victoria has made it known that Werribee will be open as usual in some way shape or form," Williams said.

"Whether those horses can be trained overseas probably depends on the government restrictions on the travel of people.

"If we have to put them in local hands, we will put them in local hands, but if they can stay in Joseph's hands, they will stay in Joseph's hands."