Opinions are sharply divided on the prospects of Caulfield Guineas favourite Long John after he drew the inside gate in Saturday's Group One classic.

In one of the most even Guineas' fields in years, Long John is as long as $4.40 in one market and more than half-a-point shorter in others.

Price assessors at betting firm Sportingbet Australia took a set against the colt after the draw, turning him out from $4.

But a spokesman for Sportsbet.com said the money continued to come for the Peter Snowden-trained runner who remained firm at its overnight quote of $3.80, the same quote as the TAB which brought him in from $4.

One member of the Long John camp not concerned about the barrier draw is jockey Kerrin McEvoy.

After galloping the colt at Flemington on Tuesday morning, McEvoy said Long John had held his form since his luckless third in last month's Guineas Prelude at Caulfield.

But he also recognised the race would be Long John's toughest to date.

"He's in great order," McEvoy said.

"His work today was as good as it's been.

"We're the favourite, but we're not over the line by any means."

The big shorteners after the draw were the New Zealander El Roca and Adelaide gelding Eclair Big Bang.

Both are in from $9 to $7.50 with Sportingbet after drawing barriers two and four respectively.

One of the biggest shorteners since Guineas betting opened is Cluster who also drew reasonably in barrier eight.

As much as 50-1 had been bet about Cluster who is now at $14 to break his duck in the Guineas.

Trainer Anthony Cummings said he expected Cluster to sit closer than when he came from near last to finish a close third in the Group Two Stutt Stakes at Moonee Valley.

"I think if he can sit closer he'll be more effective in the finish," Cummings said.

"He's a maiden, but we know he'll run a strong mile."

Second favourite in all Guineas markets is Prince Harada who drew barrier 12 and was immediately turned out from $4.80 to $5.50.