Trainer Brian Smith can reaffirm his rating as one of Australia's best trainers of stayers if My Diamantine wins the Listed Queensland Cup at the Sunshine Coast.

My Diamantine is owned by New Zealand trainer John Wheeler who had great success in Queensland with the champion Rough Habit in the early 1990s.

He sent My Diamantine to Smith in the hope of winning a major staying race.

My Diamantine has not won in Australia but she has been competitive in good races including a last-start second in the Listed Caloundra Cup (2400m).

Smith has had Saturday's Queensland Cup (3200m) in mind for My Diamantine throughout the winter.

"She was fourth in it last year, was a good last-start second and she has had plenty of miles in the build up," Smith said.

Smith has won many major stakes staying races in Brisbane including the Brisbane Cup (Balmerino, Jetset Lad), Tattersalls Cup (Hume), Grand Prix (Balmerino, Order Again), O'Shea Stakes (Balmerino) and Chairman's Hcp (Hume).

Smith was also the trainer of Australian Oaks winner Circles Of Gold, the dam of Caulfield Cup winner Elvstroem and grand dam of international performer Highland Reel.