Star sprinter Buffering will be the shortest-priced favourite on Magic Millions day at the Gold Coast as he attempts to take his earnings beyond $6 million.

The eight-year-old who lines up for his 51st start in Saturday's $1 million QTIS Quality (1300m), is as short as $1.25 to take the $600,000 first prize and lift his earnings to $6,442,266.

Trainer Robert Heathcote is only half joking when he says Buffering has earned enough frequent flyer points to travel first class.

Since he made his first trip to Sydney as a three-year-old, Buffering has been a regular traveller from Brisbane to Melbourne, Perth, Hong Kong and back.

He has clocked up about 35,000 kilometres and by the time he goes to Dubai and Hong Kong later this year it will be reaching 50,000.

"You have to admire his toughness. It is a credit to him," Heathcote said.

"We have had to manage him but he shows no signs of wanting to stop racing at the moment.

"Really if you had told me when he was a two-year-old he would be a $1.25 favourite in a million dollar race as an eight year old, I would have laughed. But here we are."

Heathcote hopes for a double with Hopfgarten in the Magic Millions Trophy (1800m) and has called on jockey Craig Williams to ride the gelding.

"Craig won two races on Volkhere for me recently and they don't come much better," Heathcote said.

"He also rode Hopfgarten when he was second in the Brisbane Handicap so he knows the horse."

The trainer had a mixed day at Doomben on Wednesday with handy mare Asadauskaite euthanised after being injured in the first race.

He later won with the John Thompson-owned Silento who was having his first Brisbane start since coming from New Zealand.

"One thing about racing - it is character building," Heathcote said.