Jake Friend's season is in jeopardy after the Roosters hooker was hospitalised by a chest injury suffered in the premiers' 24-12 defeat of Melbourne at Allianz Stadium.
Friend was admitted to hospital late on Saturday night after complaining of shortness of breath, dizziness and vomiting, and was diagnosed with a Haemothorax – a collection of blood in the pleural cavity, usually caused by a blunt trauma to the chest.
Given the short five-day turnaround and the potentially serious nature of the injury, the Tricolours rake is at long odds to be fit for Thursday night's blockbuster clash with traditional rivals South Sydney, a match that could decide the minor premiership depending on the fortunes of fellow frontrunners Manly.
Coach Trent Robinson refused to speculate on Friend's injury, though he did confirm veteran back-up hooker Heath L'Estrange should be fit to make an early return from a knee injury suffered against the Tigers two weeks ago.
Senior forward Frank-Paul Nuuausala joined Friend on the Chooks casualty list with a foot injury picked up in the 12-point win over the Storm, and is expected to miss "a couple of weeks" according to Robinson pending the result of scans on Sunday afternoon.
Roosters players were informed of Friend's plight at their post-game recovery session, and skipper Anthony Minichello admitted he was expecting Friend to spend some time on the sidelines.
"After the game he didn't look the best; he had a bit of a shoulder knock as well so he was a bit sore and said he was a bit out of breath," Minichiello said.
"But apparently he woke up and couldn't breathe and got a bit dizzy and I think he vomited, so he took himself to hospital.
"I think it's been progressive. He's had what he thought was a rib injury, and it just kept getting knocked, a few games, he got a knock at training. I think last night was just the last straw. Something happened, so hopefully he can get well soon."
An extended stint on the sidelines for Friend would be a massive blow to the Roosters' aspirations of back-to-back premierships. The 25-year-old rake, who was called into Queensland's Origin squad for the first time earlier this year, had only just returned from a hamstring injury in the last fortnight after not missing a game for the club since late in 2010.
Minichiello admitted Friend plays a massive role for the Roosters with the ball in hand, with his developing short kicking game able to take pressure off halves Mitch Pearce and James Maloney close to the opposition line.
"He's a very important part of our team," Minichiello said.
"He controls the ruck with that hooker play but he also does all that work behind the scenes that no one sees.
"He takes the pressure off the boys with their kicking and he's been putting in some grubbers recently as well. So he's got that bit of flair about him as well this year, so we certainly need him."