Originally from New Zealand, Waller has made his name in Australia and has never won a Group One race in his native country.
“I rode Comin' Through for Chris Waller in Dubai a couple of times earlier in the year and I know his racing manager Charlie Duckworth well, so the ride has come through that,” Cosgrave told NZ Racing Desk.
“Chris asked if I would be interested in going down and riding Nobu and I had never been there (NZ) before. Chris is a world-class trainer, so I have taken the opportunity to go down and see how it goes.”
The seven-time Group One-winning rider has clocked up some frequent flyer points during his career.
“I rode in the UK all summer last year and then went to Melbourne for three or four weeks to ride for Godolphin,” Cosgrave said.
“Then I came back here to Dubai in the second week of November and I've been here since.
“I'm really looking forward to getting to New Zealand, it is going to be interesting and something new and hopefully the horse will run a big race.
“I've ridden in Ireland, UK, France, Germany, Italy, Turkey, South Africa, Dubai, Australia and now New Zealand. There's not many places left, probably the only place I haven't been is the US.”