Kurt Mann has revealed how a rolled ankle became a "ticking time-bomb" that required surgery and will likely keep him sidelined for another three weeks.
The Knights utility, who has already missed his side's past four games, has been joined in the club's rehab squad by centre Bradman Best after he dislocated an eblow in Newcastle's 36-12 loss to Brisbane on Thursday.
Best is expected to miss multiple games in another blow for the Knights after it appeared their rotten run of injuries might have finally been coming to an end.
Mann, a key figure playing at lock this year, rolled his right ankle last month two days before Newcastle played Melbourne.
He spent a week rehabbing it, believing it was a normal sprain, and was preparing to play against the Bulldogs.
But while on the Sunshine Coast ahead of the Magic Round match in Brisbane, the injury became far more serious.
"I trained that day and had iced it, and I got into bed - tried to stretch my feet and this little lump popped up and it kept getting bigger and bigger and then within five minutes, I was in heaps of pain and my ankle was swollen as," Mann said.
"They initially thought I might have had a blood clot because my leg sort of changed colour and it was really hot to touch.
"I was sweating and shaking. They took me to hospital and I got checked [but] they couldn't really see anything."
Mann returned to Newcastle the next day for scans which revealed an extremely rare ruptured aneurysm.
"I got an ultrasound and found out I had torn one of my arteries in my ankle," he said.
"It was a bit of a ticking time-bomb because they don't heal themselves.
"At some stage it would have happened because I was doing a fair bit of rehab trying to get on the field. It just happened to be when I was laying in bed."
A ruptured aneurysm in an ankle artery is so rare there is almost no medical literature published about it.
"There's only a couple of cases of that known in the world," Knights head of medical Craig Catterick said.
"Kurt Mann did have a tough time."
Mann, 29, was forced to have a stent inserted via his groin to fix the problematic artery last week.
He said it had been a slightly worrying but mainly frustrating injury.
He needs to be patient to ensure a smoth recovery but hopes to now only miss this week's game against the Warriors and return after a bye against the Panthers.
"I'm in cotton wool for a couple weeks," Mann said.
"I can't really get my heart rate up and do anything to exert myself. It was a little bit worrying when they didn't know what it was, but once they ruled the blood clot out I wasn't too worried.
"It was just frustrating."
Mann, who has had multiple injuries in recent years, admitted the pain of the ruptured aneurysm was as bad as he had experienced.
"There was so much pressure in there. It goes rock-hard and was one of the worst pains I've had," the former Dragons and Storm player said.
"I've had a few surgeries, I've done my shoulder but this is probably up there with dislocating your shoulder, pain wise, just because there's so much pressure building up there.
"You're bleeding from the inside and the blood-flow out of arteries is a lot faster than a normal vein."
Best suffered a dislocated left elbow against the Broncos, rushing straight off the field into the dressing sheds.
He has had scans on his arm but the extent of the injury is yet to be determined.
Knights forward Jirah Momoisea suffered the same injury but in a slightly different way against Manly in early April and only just returned via NSW Cup at the weekend.
Fielding one of their best reserve-grade sides this year, the Knights beat the Dragons 27-20 in Sydney on Saturday.
Jake Clifford, who hadn't played since the NRL side was hammered 50-2 by the Storm, made a solid return at halfback and should provide Knights coach Adam O'Brien with another welcome selection headache this week.
Clifford and Adam Clune will now likely be vying to play alongside Anthony Milford, who made a handy debut against the Broncos.
Newcastle head north again this week to face the Warriors in Redcliffe on Saturday before a bye the following week. The Nathan Brown-coached side have lost their past three games and sit 12th, two points ahead of the Knights in 15th.
After dropping out of the side to accommodate Dane Gagai's return last week, outside-back Enari Tuala appears most likely to replace Bradman Best at centre.
However, O'Brien will soon have another selection dilemma on his hands with the experienced Hymel Hunt closing in on a return from a fractured cheekbone.
"Hymel is back in full training, but modified contact," Knights head of medical Craig Catterick said.
"His facial fractures are healing quite well. Hopefully round 13 or 14 for Hymel."