Blues first five-eighth and New Zealand Under-20 captain Simon Hickey will miss the remainder of the IRB Junior World Championship and looks likely to be out for rest of the Super Rugby season.
Hickey came off in the second half of New Zealand's final pool match against Scotland at Pukekohe's ECOLight Stadium on Tuesday. New Zealand won 54-7, and booked themselves a place in the Junior World Championship semifinals.
New Zealand Under 20 Coach Chris Boyd said Hickey had suffered a high ankle sprain that will see him out of play for approximately 4-6 weeks.
"We're obviously feeling for Simon who is disappointed his tournament is done," said Boyd. "
"He is an influential player of real calibre, so we are disappointed to be losing his skills and leadership on the field. Fortunately, we do have a couple of good options in players who have all had a run, and we know they will be keen to step up to the mark.
"Simon will continue to support the campaign and team from off the field so it will be fantastic to keep that support and knowledge in our environment."
Tasman's 19-year-old David Havili has been called in as a replacement. The former Nelson College student, was part of the national Under 20 programme through to the selection camp. He is a utility back who can cover first five-eighth, wing and fullback.