Buhrer confirmed on Thursday his decision to retire, at the age of 29, barely a day after his ex-Newcastle teammate Slade Griffin announced injury had forced him to hang up the boots.

A Hills District Bulls junior from Sydney's western suburbs, Buhrer played 173 first-grade games for Manly and Newcastle and featured in a lone State of Origin game in 2012.

He won a premiership with the Sea Eagles in 2011 after playing off the bench in their 24-10 grand final triumph against the Warriors.

He joined Newcastle in 2017 and appeared 45 times in the red and blue, co-captaining the Knights in his first two seasons.

Released by the Knights at the end of last season, Buhrer opted against extending his career in Super League because he has four young children.

He will instead return to live on Sydney's northern beaches next month and, rather than waiting to see if an opportunity might arise at a Sydney-based NRL club, will focus on completing his Bachelor of Sports Business university degree.

"There was the potential for an opportunity, but nothing that was concrete enough for me to delay the decision [to retire]," Buhrer told the Newcastle Herald.

"I could have waited a bit longer and something might have come up, but there was just as good a chance that nothing would have come along ... I would have liked to play another year, but I'm walking away with a career that I'm certainly proud of, and I haven't been forced by injury into making a decision."

Buhrer hopes his playing experience and university qualifications will eventually help him launch a career in rugby league administration.

"That's certainly something I could forsee myself doing in the future," he said.

"I feel like I've accumulated a fair bit of skill and knowledge, although obviously I've still got a bit to learn.

"One day that's where I'd like to see my future."

In reflecting on his career, Buhrer had no cause for complaint.

"People might think I was a bit unlucky with injuries, or having to play in a few positions, but really if you look back at what I was able to accomplish over 10 or 11 years, I think I've been pretty lucky, really," he said.

Buhrer's contributions on and off the field for Newcastle were recognised in 2017 when he received the annual coach's award from Nathan Brown.

Meanwhile, the luckless Griffin has confirmed his retirement after a rollercoaster NRL career, and almost immediately landed a new job with the Warriors.

The 28-year-old was unable to return to the field after suffering a devastating knee injury in June last season, requiring his fourth bout of reconstructive surgery.

He had been hoping to launch a comeback late last season, after 12 months of extensive rehabilitation and physio, but specialists advised against it, warning him there was a high chance of recurrence.

Griffin joined Newcastle at the start of 2018, having played in 25 top-grade games for Melbourne, including their 2017 grand final victory against North Queensland.

He soon established himself as Newcastle's first-choice hooker and was rewarded mid-season with his debut Test call-up for New Zealand, playing off the bench against England in Denver.

A week later, in his 16th game for Newcastle, he suffered his career-ending injury playing against the Bulldogs at McDonald Jones Stadium. His left knee buckled underneath him and he was carried from the field on a medicab.

In a social media post on Wednesday, Griffin said: "Yes I have hung up the boots.

"Sadly I was forced to retire. I'm shattered the curtain has come down on what could have been. But I'm very grateful for what I was able to achieve."

The Warriors announced on Thursday that Griffin, who hails from Greymouth on New Zealand's South Island, had accepted a development role, based in Auckland.