Andrew Fifita is in specialist care with a suspected laryngeal injury that caused the Sharks veteran breathing problems following Sunday's loss to the Knights.
The 2016 premiership-winning forward required attention from paramedics on the sidelines at Redcliffe's Moreton Bay Daily Stadium after receiving a blow to the throat in the second half from Tyson Frizell that ruled him out for the game.
After reporting further breathing difficulties after the match, Fifita was taken out of the Sharks sheds and back onto the sidelines by paramedics for another assessment, before he was placed in an ambulance and taken to Royal Brisbane Hospital.
The 32-year-old is expected to remain in specialist care this week after it was confirmed he suffered a "significant laryngeal injury"
"The Sharks can confirm that Andrew Fifita suffered an injury to his throat, following an incident early in the second half of today's match against Newcastle," a Sharks statement read.
"After the match Andrew reported difficulty swallowing. He was also noted to have a hoarse voice at this time and his care was escalated to the paramedics with a suspected laryngeal injury.
"He was taken via ambulance to hospital, where a significant laryngeal injury was confirmed.
"Andrew remains in hospital, where he is receiving the best possible care.
"The Sharks will provide further updates when they become available."