Newcastle five-eighth Blake Green has announced his immediate retirement from the NRL, saying his body simply is not up to the rigours of the game anymore.
The 34-year-old told Knights teammates on Tuesday, with the move now freeing up space in the club's salary cap for the rest of the season.
Green's retirement opens the door for Brisbane prop Matt Lodge and potentially North Queensland half Jake Clifford to join the Knights within the next fortnight.
A journeyman half, Green joined the Knights midway through 2020 and played three games before suffering an ACL injury.
He returned to play another six games this season.
"I can still see everything clearly on the field and know where I need to be, but unfortunately my body stopped getting there," Green said.
"I'm always honest with myself, my teammates and our staff.
"It hurt, but once I knew retirement was the right call I owed it to everyone to do it as quickly as possible for the betterment of our football club."
It brings to an end a decorated career for Green which took him through seven NRL clubs and 270 first-class games across 14 seasons in Australia and England.
The Knights have named Phoenix Crossland and Kurt Mann in the halves to face Manly on Sunday, with star halfback Mitchell Pearce still sidelined with a pectoral injury.