The Broncos will hold a media conference for Monday afternoon, when they are set to announce Griffin will not lead the club next season.
Brisbane players had been called to an 11am meeting at the club's Red Hill headquarters to learn about the coaching changes.
It's understood a Broncos board meeting on Tuesday will finalise Bennett's return.
In his third season in charge, Griffin has the team currently sitting sixth following their stirring 28-22 win over the Warriors at Suncorp Stadium on Saturday night.
He has received overwhelming support from his senior players and chief executive Paul White but senior board-members have worked behind the scenes to lure home their foundation coach.
Bennett won six titles in 21 years at Red Hill before leaving at the end of 2008 to link with St George Illawarra.
The 64-year-old had also been in talks with the Broncos to return at the end of 2011 but ultimately turned them down to take up a bigger $1.4 million per season deal at Newcastle.
A Fairfax Media report on Monday said a phone conversation between Bennett and News Corporation boss Lachlan Murdoch, convincing him he could return the former glamour club to their previous heights, had been crucial to the change.
News owns 67 per cent of club shares.
Former Broncos skipper Gorden Tallis, an outspoken critic of Bennett, felt the move to secure the current Knights mentor was tough on Griffin. "The players are playing for Griffin," Tallis told Triple-M radio in Brisbane.
"The Warriors came out absolutely on fire and if Brisbane weren't going to play for their coach that was the night they were going to pack their bags and go home because they would have had enough excuses.
"But they didn't. They dug deep."
Griffin only has a 46 per cent success rate in the past two seasons, but his departure won't be celebrated by his players.
Captain Corey Parker, who last week admitted reports and rumours of Bennett's return "bugged" him, gave Griffin his support again on Monday morning.
"I've got the utmost respect for Wayne, but also the utmost respect for the guy we've got," Parker told Austereo's B 105.
"I think the people we have in the organisation at the moment are sufficient.
"I've played under Wayne and he's an amazing man, but that was back in 2008 when he left the Brisbane Broncos. That's seven years by the time he gets here."
