Conn, 24, enjoyed only limited chances in two seasons with the Titans before moving to Brian Smith’s Roosters last year.
He has been an integral part of the Bondi club’s march to the finals this season and says Friday’s clash is just business.
“I don’t really have anything to prove to them,” said Conn.
“I think all of me being consistent this year just comes down to the coaching staff and having a bit of an attitude.
“When I go up there I’ve got nothing to prove. I’m going to go out there and do the best I can for the team and myself and hopefully that will be enough to get us over the line.”
The Titans will have the benefit of a 14-day rest going into the game, but Conn says the Roosters will be concentrating on their own game.
“We can’t worry too much about that,” Conn said of the rested Titans.
“We’ve got to fix a few little things we let slip last week in our last game. We just need to focus on what we need to get right this week.
“I think we might be a good chance as underdogs this week,” he said.