Newcastle co-captain Jamie Buhrer will miss the rest of the NRL season after suffering an ACL tear as the Knights copped a deflating 18-16 loss to the Sydney Roosters.
For the second week in a row, winger Blake Ferguson was the Roosters' hero with his tries either side of halftime proving the difference.
The game went down to the wire after Newcastle fullback Kalyn Ponga scored with just four minutes remaining but the Knights wasted their chances in the final moments.
Worse still, their injury worries hit crisis point at McDonald Jones Stadium after Buhrer suffered his third ACL injury in five years.
Forced from the field midway through the first-half, he cut a forlorn figure afterwards in the sheds, wearing a knee brace.
It's a bitter blow for the 28-year-old whose 2014 and 2015 seasons were also ended by ACL injuries.
"Throughout his career he's always had a few big injuries but he's always seemed to bounce his way back," Knights coach Nathan Brown said.
"He's disappointed, as is the case when anyone gets a long-term, season-ending injury. Obviously he's starting to get on to the latter part of his career as well. He's not a young bloke anymore.
"But he'll be right, he'll bounce back and rehab well and I'm sure he'll get back on the field next year and play some good footy."
Buhrer joins Mitchell Pearce, Tautau Moga, Daniel and Jacob Saifiti and Nathan Ross on the Knights' injured list as they suffered their fifth loss in six games.
Trent Robinson's men also had plenty of excuses but refused to give in.
They were made to do it tough after skipper Boyd Cordner withdrew, having pulled up sore from Wednesday's State of Origin opener.
His fellow Blues Latrell Mitchell -- who set up the opening try for Luke Keary with a powerful individual effort in just the fourth minute -- and James Tedesco were also outstanding.
Dylan Napa, who was also backing up, was sin-binned in the 54th minute under dubious circumstances.
When he locked up Herman Ese'ese close to his own line, he had his arm trapped in the tackle but was marched for not getting up quick enough.
However the Roosters shook off their setbacks to collect a valuable two points.
Ferguson gave his side a 12-8 halftime lead when he burst onto a sweetly-time Keary ball and pushed them further ahead two minutes after the resumption when he stormed down down the short side and steamrolled Ken Sio.
"I was very pleased -- the boys backing up -- as we've seen over the weekend it's a big task," Robinson said.
"They did well. Newcastle had their trials and tribulations as well and it ended up being a contest."