Parramatta are expected to make a major offer for Bradman Best if he remains unsigned when the November 1 negotiating period opens.
Journalist Michael Carayannis told Fox Sports' NRL 360 that Best is the Eels' leading target.
"I think he's their number one target," Carayannis said.
He said Parramatta had identified Best as a long-term centre and would make a significant move if he reached the deadline without a deal.
Best has indicated he is in no rush to re-sign with Newcastle, although he took the same approach last time before ultimately staying with the Knights.
"Obviously there's a fair bit of talk going on with that November 1 around the corner," Best told 9NEWS a fortnight ago.
The coming free agency period is expected to be the game's biggest, with a rising salary cap and the tax-free funds available to new club the PNG Chiefs.
The Chiefs have already signed Alex Johnston, Brian To'o, Zac Lomax and Joseph Manu, making further big-name outside-back recruitment unlikely.
Parramatta need outside-back options after Sean Russell and Apa Twidle agreed to join the Perth Bears at the end of 2026; Josh Addo-Carr's future is uncertain following an alleged off-field incident.
Brian Kelly, Araz Nanva, Jordan Samrani and Bailey Simonsson are among the Eels off-contract after 2027, giving coach Jason Ryles scope to reshape the squad after a poor 2026 season.
Newcastle have also been linked with Jack Bostock, adding to concern they may not retain Best.