Kauto Star has been trimmed to 7 to 4 favourite from 2 to 1 with the sponsors for the William Hill Tingle Creek Trophy Chase at Sandown Park on Saturday.
The Haldon Gold Cup runner-up, the mount of Mick Fitzgerald, is one of four Paul Nicholls-trained entries in the Grade One two-mile feature.
Bookmakers also reported support for one of his stable companions, Sporazene, with Coral cutting the grey's odds to 6 to 1 from 10 to 1 following decent support.
"With last year's one-two-three of Moscow Flyer, Azertyuiop and Well Chief all missing from this season's renewal, this is a wide-open betting heat, and the support for Sporazene confirms this," said Coral spokesman David Stevens.
As well as money for Kauto Star, Hills reported interest in Oneway and clipped Mark Rimell's charge from 9 to 1 to 7 to 1.
Philip Hobbs is leaning towards running Monkerhostin in the Sandown feature.
The Minehead trainer is favouring a return to two miles for the consistent gelding rather than the Robin Cook Memorial Gold Cup over an extra five furlongs at Cheltenham seven days later.
Monkerhostin, a 5 to 1 chance with Hills, has shown himself to be a versatile and hardy performer this season.
He defeated Kauto Star in the Haldon Gold Cup at Exeter before finishing second in the Paddy Power Gold Cup and the totesport Peterborough Chase.
Hobbs reports Richard Johnson's mount to be in fine fettle and sees no problem with a return to the minimum distance.
"He won well over two miles and a furlong at Exeter, and although I've been looking at the Robin Cook Chase, I would have thought the Tingle Creek looks favourite at this stage," said Hobbs.
Locksmith, generally available at 25 to 1, warmed up for Saturday's big race by working on Martin Pipe's gallops yesterday morning. At the age of five, the grey is the joint youngest entry along with Kauto Star.
Ireland will be represented by Rathgar Beau and Central House.
William Hill betting: 7-4 Kauto Star, 7-2 Ashley Brook, 5-1 Monkerhostin, 11-2 Rathgar Beau, 7-1 Oneway, 10-1 Central House, 14-1 Sporazene, 25-1 Hand Inn Hand, 33-1 bar.
