Steve Gillis, who manages Finch and Rogers, said he had "opened negotiations" with Onslow about Rogers but the Knights were yet to make a formal offer.
"We've begun talking. I need to sit down with Benny and see where he's at and just work through it but as far as I'm aware, he's very happy at the club," Gillis said about Rogers, who has been sounded out by a European rugby union club.
As for Finch, Gillis said the Knights had not made an offer.
"I've read what they've said [about Finch] but I don't know whether the club knows which direction it's going to take, so I'm certainly not going to rush them," he said.
"If they're interested, they'll make an approach in their good time."
Onslow confirmed he had spoken to Gillis about Rogers but said there had been no formal discussions about Finch, the former Knights ballboy who has played a total of 242 NRL games for the Raiders, Roosters, Eels and Storm and won a premiership with Melbourne last year.
In the current issue of Rugby League Week magazine, Finch said: "Being a Newcastle boy, I would definitely be interested if something came that way."