McDonald will team up with the man who gave him his first Group 1 win in Australia – Scarlett Lady in the 2011 Queensland Oaks – when he rides Sharp 'N' Smart for Graeme Rogerson and his wife Deborah in the Derby.
The son of Redwood was ridden to Spring Champion Stakes (2000m) victory by Hugh Bowman but Bowman's decision to remain in Sydney for the Golden Eagle meeting paved the way for McDonald to snap up the Derby mount.
The Derby remains absent from the list of 72 Group 1 successes for McDonald, whose best result is a second placing aboard Etymology in 2015. He has also been unplaced twice aboard favourites, in 2011 when seventh on Dundeel and 14th on Savvy Nature the following year.
Sharp 'N' Smart's Spring Champion performance convinced McDonald he is capable of finally giving him some Derby joy providing he handles the seven-day back-up and trip down from Sydney.
"He was amazing, to soldier it out like he did was a phenomenal performance after doing a little bit of work through the mid-stages and being caught wide," McDonald told RSN927's Racing Pulse.
"He's a lovely pick-up ride. As long as he travels down OK, the week's back up is obviously a question mark, but he looks a nice ride."
Sharp 'N' Smart was one of 18 nominations for the Derby with fellow Kiwi, Mr Maestro, Saturday's Moonee Valley Vase winner Berkeley Square, Pericles and Muramasa ad Grand Pierro among his potential rivals.