After losing to Samoa by 28 points, the news for Tonga has gone from bad to worse with star front-rower Stefano Utoikamanu ruled out of next week's must-win clash against the New Zealand Kiwis.

One of the stars on show in the clash between Samoa and Tonga, Utoikamanu's debut for the international side lasted only three minutes before he was forced from the field.

Failing to return to the contest, the NSW Blues front-rower suffered a concussion after a heavy shot from opposing forward Francis Molo who was placed on report and could catch the attention of the match review committee.

As a Category 1 HIA, Utoikamanu will be unable to play in next week's must-win clash against New Zealand due to the mandatory 11-day concussion protocols.

Needing to defeat the Kiwis by at least 23 points to make the 2025 Pacific Championships final, Tonga will be hoping to receive Jason Taumalolo back, who is currently racing the clock to be fit.

Missing the clash against Samoa, the nation's co-captain is on the mend from a knee cleanout and while it was hoped that he would be available, he is still recovering from the operation.

"He obviously had end-of-season surgery, and it was always a little bit of a rush trying to get him back for that game, and that's what we all aimed to do, including him," Woolf said.

"I just felt when I watched a few things and when I watched some training vision and him running ... that it wasn't the right thing to do by him to play and that it was just a little bit too soon.

"My job as a coach is obviously to try and put us in a position to win games but it's also to look after our players, and I thought he needed to be looked after a little bit, and I thought we're gonna put him at risk if we throw him out there.

"He'll be right to go [on Sunday]; he'll have another week of running under his belt."