Chiefs' injury crisis deepens
Brown will undergo surgery and is expected to return to play in six to nine months.
The Chiefs also announced utility back Shaun Stevenson has undergone surgery on his knee following an injury sustained during warm-up against the Blues in Round Three, ruling him out for at least four weeks.
Lock Fin Hoeata is also out for an extended period after he sustained a shoulder injury at training. He is set to undergo surgery and will be sidelined for six to nine months.
All Black Dominic Bird, who injured his shoulder in the Chiefs' first match of the season, is still being assessed.