Who is next on the Newcastle Knights' retention hit list?

Best has agreed to terms on a three-year extension, which the Knights will announce once it has been formally rubber-stamped by the NRL, capping off a productive off-season for Newcastle football director Peter Parr.

Best, fellow NSW Origin representative Jacob Saifiti and much-improved utility Phoenix Crossland were Newcastle's obvious retention priorities, and Parr has successfully signed, sealed and delivered all three.

Parr is expected to let the dust settle before turning his attention to the likes of Gagai, Tyson Gamble, Mat Croker, Enari Tuala, Brodie Jones, Krystian Mapapalangi, David Armstrong, Myles Martin and Ryan Rivett, all of whom are out of contract at the end of this season.

Gagai, a veteran of 268 NRL games, 22 Origins and seven Tests for the Kangaroos, is Newcastle's oldest player at 33, but his form last season was as good as at any point in his 14-year career.

Parr told the Newcastle Herald there had been no discussions with Gagai yet about extending his stay and that could wait until the season was under way.

"Like a number of players at the club, we'd probably like to see Dane play a bit of football first," Parr said.

"So that's my expectation at this stage, unless his agent was to approach the club about starting talks earlier.

"I don't see it as being a lot different to Tyson Frizell 12 months ago.

"He was happy to play some footy - see what the form is like, see what the body is like - and see what transpires after that.

"I haven't had that conversation with Dane yet, or his agent, but I'm sure we'll have it at some stage, when the timing is appropriate."

The Knights eventually re-signed Frizell, their second-oldest player, to a three-year contract that included release clauses at the end of the next two seasons.

Parr said Gagai was still a quality performer, at an age when the majority of players have already retired.

"His form was really good last year," he said.

"He played a lot of games, he was really consistent, and he's been a very good player for a long time.

"With any player, when they're nearer the end of their career than the start, you have to make sure their form and their body are in good order.

"Dane certainly ticks both those boxes, and he also offers vast experience and great leadership skills."