A 36-20 preliminary-final victory over the Dolphins has put Daly Cherry-Evans one win away from his third grand final.
The 37-year-old said he expected a premiership opportunity when he joined the Sydney Roosters, given their roster and coach Trent Robinson's program.
After 352 games for Manly, where he won the 2011 title in his first season and later captained the side, Cherry-Evans said his Roosters move was not about payback.
"I've got to be honest, my motivations are so internal. It's those storylines that might be created around Manly, it's honestly got nothing to do with why I've continued to play the game of rugby league," he said.
"I'm way more internally motivated than trying to stick it up anyone. I'm too old for that, honestly," he added.
His move to Super League club Hull FC next year surprised outsiders, but he said accepting this would be his final season felt right for his family.
"I can't explain it any more than the feeling was just so right for the family and I to accept that whatever happens this year is going to be the end," Cherry-Evans said.
He said that decision sharpened his focus and increased his hunger to finish with a premiership.
Cherry-Evans said the Roosters had been working towards this opportunity since November, but stressed the job was not complete.
"The job is certainly not done yet. I'm super proud, and we're exactly where we want to be," he said.
His 2011 grand final win, when he was 22, will guide him as he prepares for the coming week; he is now 37.
"I'll remember that day for the rest of my life … knowing what's on the other side of this 80 minutes, I'll be doing whatever it takes this week.," he said.
Cherry-Evans said a premiership would be a lifetime memory, adding, "I love this game, and if I could finish with a special moment like a premiership, then it'd be a lifetime memory, no doubt about it."