GP winner Billy Mackenzie has been forced out of the MX Nationals championship chase. Image: Alex Gobert.

Monster Energy Kawasaki’s Billy Mackenzie will sit out three to four months of the Monster Energy MX Nationals through injury following his incident-filled weekend at Coonabarabran in New South Wales.

The Scotsman finished 18th overall after a spate of incidents at Goanna Tracks in all three motos, however it is a torn ligament in the scaphoid region of his arm that has forced him out of the title chase.

Mackenzie suffered the injury in a heavy moto two crash while running in a top three position, a bitter blow while displaying the speed required to battle for victory before his mishaps.

It’s believed that Monster Energy Kawasaki is now on the search for a replacement rider alongside four-time champion Jay Marmont on the Pro Circuit-equipped KX450F for the foreseeable future.

With Australia’s leading contenders all locked in to seats for the full season, speculation is mounting that the Queensland-based team is looking toward talent in the U.S.

The team has had great success previously with American riders, including Josh Hansen’s dominant win in the Australasian Supercross Championship during 2010.

Australian motocross will continue at Wonthaggi in Victoria for round three on 28-29 April.