Glen Rocco has headed the ante-post market thanks to two fine runs on the Sunbury course.
On the first occasion he was second to Glen Forsa - a leading fancy for the Arkle Trophy at Cheltenham - and followed that up when winning by 23 lengths last time.
Gifford believes the horse has to improve after the handicapper put him up 13lb.
"He's in very good form. He got hammered for winning a race that fell apart. We'll see," he said.
"It's a lot more competitive than the race he won there last time. He's going to have to improve.
"All the boxes are ticked. He loves the ground, he loves the track. He's got a nice weight. Whether he's good enough, time will tell.
"It was the obvious race for him. It's a great pot, and we're just excited to be running in these sort of races.
"This is a whole different ball game. But he deserves to take his chance, and we're hopeful he'll be bang there."
Owner Matt Morgan is hoping for a good run from the Nicky Henderson-trained Rather Be, who carries his colours.
The eight-year-old was unlucky to be brought down in the BetVictor Gold Cup at Cheltenham, but got round when fifth to Frodon in the Caspian Caviar Gold Cup there on his last start in December.
"He's had a bit of a break, he's got his ground on Saturday - and if he's ever going to get three miles it will be on good ground at Kempton - so the boss (Henderson) has said 'let's give it a try'.
"The favourite (Glen Rocco) looks like an improver. But they are talking about him in terms of a Grand National horse, and he's got a hefty rise to overcome.
"We've always said there's a big pot in him - it's just finding that day. There doesn't seem to be any excuses - it's just whether he stays. But he stays two-five at Cheltenham well enough."
Catamaran Du Seuil was behind Rather Be when eighth to Frodon but ran a good race as runner-up to Calipto at Wincanton in January, and trainer Dr Richard Newland is optimistic of decent show.
"He's in good form. We've just given him plenty of time after his last run," said Newland.
"We missed an engagement when the meetings were cancelled (for equine flu), so we decided to wait for this - and I hope he'll run really well."
Sam Twiston-Davies has won and finished second on Walt recently, and trainer Neil Mulholland is hoping the combination can click again.
"He's run well the last couple of times. He likes the nice ground and he's fresh and well," said Mulholland.
"He's got a nice weight, and Sam Twiston-Davies has had a good connection with him the last couple of runs."
