Angus Crichton will join Roosters assistant Michael Cheika at the NSW Waratahs in 2027, targeting selection for the Wallabies' Rugby World Cup squad.
Before that move, the 30-year-old wants to finish his eight-year Roosters career with premiership success.
Crichton feared his season was over after suffering a serious foot stress fracture in Round 15.
He returned during the 46-10 victory over the Sharks after 12 weeks out and is expected to retain his impact role from the bench against the Dolphins.
"I've been in this club for eight years now," Crichton told media at Allianz Stadium on Monday.
"I love this club, I love the boys, I'm so determined to come back and be part of this."
He accepted coach Trent Robinson may again use him as an energetic replacement in Friday night's preliminary final.
"I'm down to do that… whatever the team needs to win, that's what I want to do."
Crichton also hopes to depart alongside fellow outgoing players Mark Nawaqanitawase and Daly Cherry-Evans, with the Roosters still seeking their first grand-final appearance since 2019.
"There's only one way I want to leave this club… it's been a long time since we've done much at the Roosters," he said.
He has made 157 appearances for the club since leaving arch-rivals South Sydney in 2019.
"This club deserves success and it demands success," Crichton said.