Kiwi Cody Cooper has been ruled out of this weekend's Appin round of the MX Nationals.

Team Rockstar Motul Suzuki’s Cody Cooper has officially been sidelined for this weekend’s third round of the Rockstar Energy Drink MX Nationals, Australian Motocross Championship.

Cooper won moto one at Appin last weekend and was in the same position when he crashed on a technical uphill double at the Sydney-based circuit, ruling him out of proceedings.

According to Suzuki Australia general manager, Motorcycles, Perry Morison, it was revealed that Cooper had collapsed a lung and suffered a severe rib injury upon a precautionary visit to hospital on Sunday evening.

Cooper then spent three nights in hospital in order for doctors to monitor his progress, ruling the recently-crowned New Zealand champion out of Raymond Terrace this weekend.

After finishing second at the season opener and dominating the opening moto at Appin, Cooper’s injury comes as a severe blow in a season where consistency will be key in order to win the Pro Open title.

The injury for Cooper leaves Suzuki’s factory Suzuki effort with just Daniel McCoy in the Lites, while satellite rider Lawson Bopping is again expected to excel for Raceline Pirelli Suzuki.