Co-trainer Trent Busuttin admits he did not expect Jack Regan to be taking on Melbourne Cup winner Vow And Declare when he was planning his assault on a staying race at Flemington.

After Jack Regan won successive races at Sandown, Busuttin picked out Saturday's William Newton VC Handicap (2600m) as a suitable assignment.

But the presence of Vow And Declare, who will carry 61kg in the quality handicap, has put a different slant on the race.

"It's to their advantage so why not run, but you don't expect to be running into a Melbourne Cup winner in these types of races at this time of year," Busuttin said.

"He's got two or three less kilos than he should and we should be on the minimum with 54 kilos.

"He's thrown in at the weights, but 61 kilos over 2600 metres, it's still a bit of weight."

To compound Busuttin's woes, regular rider, apprentice Thomas Stockdale, is suspended.

Busuttin said Stockdale's claim, which would have reduced the stayer's weight to 53kg, may have helped.

Instead Mark Zahra takes the ride at 56kg.

An English import, Jack Regan broke through for his first Australian win at his 10th attempt.

Busuttin put Jack Regan's improvement down to jumping session an the fact he had finally acclimatised to Australian conditions.

Busuttin plans to tackle the Andrew Ramsden Stakes (2800m) at Flemington on May 16 wiht Jack Regan to try to gain ballot exemption into this year's Melbourne Cup.

But Busuttin is realistic about the quality of the opposition Jack Regan has defeated at his past two starts.

"He had only been working fairly but leading into his last win he worked like a good horse and he worked like a good horse on Tuesday as well," Busuttin said.

"But at the end of the day he won a benchmark 70 and then beat up on a moderate 84 ratings race last time.

"We're not getting carried away, but the way he put them away last time, he did it well."