Injury blow for All Black contender
The Crusaders pivot suffered a suspected broken jaw in his team's 45-28 win over the Stormers in Christchurch on Saturday.
Mo'unga was taken to hospital after colliding with the Stormers' Springbok prop Steven Kitshoff in the final minutes of the Super Rugby Round Three clash.
"It was just a head clash," Crusaders coach Scott Robertson said.
"It was when their reserve prop scored, he [Mo'unga] took one on the chin. He sort of fell off that tackle when they scored."
Mo'unga, who played for the All Blacks against a France XV last year, is a leading contender to fill the void as New Zealand's number two flyhalf behind Beauden Barrett following Lima Sopoaga's decision to move to English side Wasps after the Super Rugby season.
Before being forced from the field, Mo'unga scored a try and landed five conversions.
"It is a shame for him. It is similar to what happened last year isn't it?" Robertson added, in reference to Mo'unga being sidelined for six weeks in 2017 when he broke his left hand in the Crusaders' first game of the season against the Brumbies.
The Crusaders, Super Rugby's defending champions, already have All Blacks Kieran Read, Matt Todd, Israel Dagg, Owen Franks, Joe Moody and Tim Perry unavailable because of injury.