Danny Buderus has been released from hospital after scans cleared the retiring Newcastle hooker of any serious head or neck injuries.
Playing what would prove to be his 257th and final game in the NRL, Buderus was taken from the field just 17 minutes into Saturday night's preliminary final loss to the Sydney Roosters after being knocked unconscious trying to tackle Roosters prop Jared Waerea-Hargreaves.
The 35-year-old was rushed to hospital and kept there overnight as a precaution.
He was discharged yesterday to return home.
A statement on the Knights website confirmed there were still some concerns over Buderus' lower back, the former NSW and test representative having undergone two back operations this year.
"No one wants to finish their career this way but I have been fortunate to play the game I love for this long and for us to finish in the top four this season," Buderus said.
"Thank you to everyone for their well wishes and support, not just last night but throughout my career.
"I love this club and have said on a number of occasions I am forever indebted to it."
Relief for finalists as pair cleared
Both NRL grand finalists breathed a sigh of relief yesterday with star Manly back-rower Glenn Stewart and explosive Sydney Roosters centre Michael Jennings cleared to play in next weekend's decider.
Both were charged over incidents in their team's preliminary finals wins, but neither offence was serious enough to force a suspension.
Stewart, 29, endured a nervous wait from the Sea Eagles' 30-20 win over South Sydney on Friday, when he hit Rabbitohs enforcer Sam Burgess high in the fourth minute.
But the two-time premiership winner escaped with a grade one careless high tackle charge.
Jennings was charged with tripping Newcastle's Akuila Uate in Saturday's heavy win over the Knights, but his grade one offence will also not affect his maiden grand final appearance.