Betting lines on Saturday's $2 million (Australian funds) Australian Derby (Aust-I) suggest Niello is facing a far from easy task to become the fifth colt to win Australia's Triple Crown.Lonhro's younger brother is a 3-1 third favorite with most major off-track bookmakers to cap successes in the Canterbury and Rosehill Guineas (both Aust-I).Some have him a 7-2 chance behind Starcraft and high class filly Special Harmony. Quotes vary but they are generally around 7-4 and 9-4 respectively.Niello has the hometown popularity as he's by Octagonal, the last Triple Crown winner in 1995. He is also the only one to manage it since the Derby and its major prep races moved from spring to fall in 1979.Niello is unbeaten in three races beyond a mile, all at group I, collecting the 2,000 meters Spring Champion Stakes last September. Yet some consider him suspect at 2,400 meters of the Derby on a slightly damp Randwick, and believe Grand Zulu should have beaten him in the Guineas before taking the Tancred (Aust-I).Starcraft had a training setback between his win over older horses in the Chipping Norton Stakes (Aust-I) and the Tulloch Stakes (Aust-II) on April 3. One race later at Rosehill, Special Harmony scored a hard-fought win in Oaks prep, the Arrowfield Stakes (Aust-I), also over 2,000 meters.Special Harmony is bullet proof at the distance on the strength of her Victoria Oaks (Aust-I) at 2,500 meters last spring. She has been head-and-shoulders above the fillies and, given a firm track, can become the first female Derby winner since Research in 1989.Niello will possibly always reside in the shadows of his dad and brother. But he can take a step into the spotlight by closing out the Triple Crown.Woodman's Preakness winner Timber Country is the only sire with two Derby runners. A soft track would bring his filly Timberina (20-1) into calculations; his colt, Lord of the Land, is 100-1 despite a battling fourth in the Rosehill Guineas.