Mornington trainer Paul Rocke didn't quite know what he had when he bought Nisos - but he certainly didn't think the gelding would be lining up in Saturday's $1.5 million Victoria Derby at Flemington.

It was Nisos who more or less planned his own destiny and while he is not expected to challenge his glamour rivals, a top five finish would prove an important boost for Rocke's 10-horse stable.

He described the horse as "a nice, neat colt" but as he learned his strengths, his program changed considerably.

"When I bought him I didn't think he was a Derby horse," Rocke said.

"I thought he was a very athletic horse that might have run as a two-year-old.

"But as I trained him and time progressed I couldn't find the bottom of him.

"Aerobically he never seems to blow, he never seems to get tired."

It wasn't long before Nisos was looking for longer trips and ultimately the Derby came onto the radar.

"After we gave him a couple of runs we mapped out a plan for the Derby and it's gone pretty much to plan," he said.

"Just the way he raced in his first prep. All he wanted to do was settle and hit the line.

"And he kept pulling up after his races so well in the wind that further seemed better."

A run at Swan Hill over 1300 metres settled the issue.

"He missed the start and from a long way back he ran on like a good staying two-year-old into fourth place and after that I gave him five weeks in the paddock then mapped out the plan," Rocke said.

Nisos ran fifth of seven starters in the Group Two Moonee Valley Vase (2040m) on October 27, which was an advantage according to Rocke.

"Obviously having that soft run last Saturday was a blessing because he was probably never going to win that race but having a soft race means he's come out of it feeling very well and very bright," he said.

Nisos has barrier three and Rocke wants him near the tail of the field early.

"We'll let him go to sleep until the turn and then from the half mile we'll put him into the race and we'll see if he's good enough," he said.

Nisos will be ridden by Billy Egan who was aboard when he was a close third in the Listed Hill Smith Stakes at Morphettville two states ago.