Tidal Bay heads the weights after 22 horses were confirmed for the Hennessy Gold Cup at Newbury on Saturday.
The enigmatic 11-year-old ended last season with victory in the bet365 Gold Cup at Sandown and made a winning return back over smaller obstacles in the John Smith's Hurdle at Wetherby.
Champion trainer Paul Nicholls could also saddle Harry The Viking, who is at the other end of the weights on 10st 2lb, but stable companion Michel Le Bon is a notable defection.
The ante-post favourite for the race is Nicky Henderson's Bobs Worth (11st 6lb), last seen winning the RSA Chase at the Cheltenham Festival. Henderson may also saddle Roberto Goldback, who made a winning start for new connections at Ascot.
Other leading contenders include The Package, Hold On Julio, Frisco Depot and Saint Are. Last year's Hennessy hero Carruthers is also in contention - as is the 2010 winner Diamond Harry.
There is also a strong representation from Ireland, headed by the Mouse Morris-trained First Lieutenant.
Irish National winner Lion Na Bearnai and Magnanimity from Dessie Hughes' yard may also make the journey.
Frisco Depot's trainer Charlie Longsdon is hopeful of a bold run. The eight-year-old showed smart form for Hughes in Ireland and was in the process of running a big race at Ascot on his debut for Longsdon when falling three fences from home. Sam Waley-Cohen, son of part-owner Robert, will keep the ride this weekend.
Longsdon said: "It was the lightest Sam had ever ridden when he rode him last time. He will probably do 2lb over weight on the day and I think we will put a stronger bit in his mouth because he was a bit keen last time.
"I don't think the ground will be a problem as all his runs in Ireland were on heavy ground."
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Quevega five-timer still on course
Wylie trio go for Gold
Cyclone blows into Punchestown
Rain set to help Punchestown
Rifles aimed at York
Dante considered for Arod
Carpenter faces stamina question
Tonto strives for Sandown scalp
Telescope sights fixed on Sandown
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Un De Sceaux to skip Punchestown
Treve among stellar Ascot entries
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Prince in Punchestown frame
Sparrow set for Punchestown spin
Balder to take novice test
Connell eager for Tank chase run
23 April 2014Telescope tops Richards runners
No rush for Annie target
Cosgrave appeal set for Monday
Hughes set for Sandown return
France adds flair to Guineas
Mullins drops Vautour Champion hint
Exciting Bunker given Dante date
Culloty keen on Gold run for Heeled
Hannon triple-handed in Guineas
Resurge revived for Epsom return
Sandown option for Battalion
Johnston pair clash in Derby Trial
Reckless Abandon returns to track
22 April 2014Rizeena delights in Guineas workout
Carberry targets swift return
Williamson escapes serious injury
Rizeena thrills Brittain on gallops
Door bags National glory
Twiston-Davies hits four-timer
Joe suffers shock defeat
Scudamore hits century mark
Ivan lands Fairyhouse prize
Thousand shows star quality
Cirrus set for Treve clash
Houblon heads Gold contenders
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21 April 2014Door bags National glory
Wilson passes away
Ivan lands Fairyhouse prize
Stepper set for trip drop
Richards in Telescope sights
Ladies geared for Summer repeat
Hill out of Irish National
No Dundeel at Royal Ascot
Clowance up for the Cup
Garner hit with lengthy ban
Memories in Final flourish
Fitz powers home at Fairyhouse
Toner hits target for Elliott
Joe ready for Cork outing
Lennon looking to call tune
Ground holds key to Tonto show
Lucky escape for Cook
Mind called up for National service