Blues captain and All Blacks flanker Dalton Papalii is expected to miss Saturday's quarter-final with the Highlanders at Eden Park and be sidelined for several weeks due to a medical issue.
The Blues declined to comment when approached, saying the matter was private, but the Herald understands Papalii could missthe remainder of the Super Rugby season and be in doubt for the All Blacks' three-test series against Ireland next month.
Papalii was named to start at openside flanker for the Blues, alongside Akira Ioane and Hoskins Sotutu, against the Highlanders but the medical issue is believed to have since flared up and he is understood to have had key hole surgery.
The 24-year-old has been an inspirational skipper for the Blues this season, leading the team to a record run of 13 unbeaten matches.
The Blues are likely to promote Adrian Choat from the bench as they are already missing Anton Segner following his ankle injury last week.
While his prognosis is better than first feared, Papalii's absence would be a huge blow to the All Blacks. Even if Papalii returns in time for the first test against Ireland at Eden Park on July 2 he would be lacking game-time.
Last year he firmly established his presence by starting eight tests, and his abrasive qualities would be welcomed against Ireland with speculation he could have been used in the blindside role.
All Blacks coach Ian Foster was dealt another blow on Friday night with impressive Crusaders loose forward Ethan Blackadder departing in the 62nd minute of their 37-15 victory against the Reds in Christchurch with a concerning wrist injury.
After a superb performance from openside flanker at the breakdown and with ball in hand, Blackadder was in serious pain when he left the field and is likely to face an extended stint on the sideline.
Losing both Papalii and Blackadder, the latter featuring in nine tests last year, would force Foster to significantly reshape his loose forward plans for Ireland.
News of Papalii and Blackadder's aliments comes as All Blacks halfback Aaron Smith is expected to be ruled out for the Highlanders with a groin injury that could sideline him for three weeks.
Tongan-born All Blacks prospect Folau Fakatava is likely to take Smith's place in the Highlanders starting side, with Kayne Hammington moving onto the bench.
