Otago assistant coach Ryan Bambry confirmed the 28-year-old injured his medial collateral ligament during the tense 44-41 win over Waikato in the NPC quarterfinal.
It is not clear how long Timu will be sidelined for, but he is definitely out for the semifinal.
The centre missed the entire 2025 Highlanders campaign and played just two NPC games in 2024. He has had more than his share of bad luck with injuries.
His form this season, especially on defence, has been impressive. He has been able to build nicely throughout the season.
"He’s been awesome and it’s been great to have him back after quite a lengthy absence through injury," Bambry said.
"He’s been a hugely critical part of our team, so I’m gutted for JT that he’s not going to be able to play on Friday night.
"But Josh Whaanga has been excellent as well and we have all the faith in him to come and do a job."
Otago will name their team today.
They have not been beset by a huge number of injuries this season.
However, they have lost the services of massive prop Saula Ma’u, and hooker Henry Bell broke his collarbone, which has stripped some quality from the front row.
Former All Black Liam Coltman was previously starting from the bench and leading the effort in the final quarter of the game.
Otago tended to finish games strongly.
But Waikato came back hard in the quarterfinal and North Harbour gave them a fright late during their round nine game.
Bambry said they were aware they had not closed a couple of games as well as they could, but he did not feel it was part of an emerging pattern.
"I don’t think so. We definitely reviewed it as a whole team and we’ve reviewed the last 12 minutes [against Waikato] and come up with solutions around how we can be better there.
"But we certainly don’t believe that it’s a problem area for us.
"We don’t want to make a big deal of it. We just need to ensure that the solutions that we come up with mean we can do better on Friday night if we’re in that position again in the back half of the second half."
Otago led 38-22 with 20 minutes to play. Waikato roared back but Cameron Millar drilled a clutch penalty on fulltime to seal the win.
"I’ve never believed in a goal-kicker like I have in Cam Millar. I just knew he was going to bin that.
"I couldn’t be happier for Cam for that to happen to him and for him. He works incredibly hard at his craft and he got what he deserved."
Now on to Bay of Plenty.
The two teams have not met this year, but the Steamers have been one of the best teams in the competition for the past few years.
They were beaten finalists last season and have been consistently good this year as well.
