Crusaders first-five Richie Mo'unga is facing a lengthy stint on the sidelines after suffering a suspected broken jaw during his side's 45-28 win over the Stormers.
Mo'unga was taken to hospital after trying to prevent Stormers prop Steven Kitshoff from scoring a try in the final minutes of the match at AMI Stadium in Christchurch on Saturday.
Crusaders coach Scott Robertson said his first-five had had scans but didn't know the full extent of the injury.
"It was just a head clash," Robertson said.
"It was when their reserve prop scored, (Mo'unga) took one on the chin. He sort of fell off that tackle when they scored.
"It is a shame for him. He is away getting X-rays now."
Mo'unga missed six weeks of last year's Super Rugby competition after he broke his left hand against the Brumbies and required surgery. He then broke his right hand late last year during the All Blacks end of year tour.
Before being forced from the field, the 23-year-old scored a try and landed five conversions for the defending Super Rugby champions.
The Crusaders face the Hurricanes in their next match on March 10.