Warriors wantaway Blake Green could turn out for Newcastle on Saturday against Canterbury after being granted an immediate release by the New Zealand NRL club.
Green will be reunited at the Knights with coach Adam O'Brien, with the pair working together for two years in 2015-16 while at Melbourne.
Slotting into the halves, Green's recruitment could allow Kurt Mann to move to hooker where Newcastle have an injury crisis with three players out for the season.
Newcastle will be 33-year-old Green's seventh NRL club, while he also spent four years in the Super League.
Warriors chief executive Cameron George confirmed the release, saying Green had informed his teammates of his departure early on Tuesday.
Given the club had told Green he wasn't required beyond 2020, George said they needed to allow him to take up the Knights offer as it could provide a future for him.
"Blake has requested through his manager for a release and that's been granted immediately," George said on Tuesday.
"He's a champion person and has been a great player for a long time and in recent years for our club.
"This decision with Blake heading off today might provide him with a further opportunity in the future ... we wish him all the best."
Australian Associated Press