Chris McQueen in action with Luke Keary at the Rabbitohs back in 2014.

Back-rower Chris McQueen has issued his fellow Titans with a warning ahead of their Round 1 showdown with the Roosters, stating that former Rabbitohs teammate Luke Keary possesses one of the smartest football brains in the game.

Keary will make his debut for the Roosters at Cbus Super Stadium on Saturday night alongside Mitchell Pearce, one of only three halves combinations named for Round 1 to have both won premierships.

‌Keary and McQueen played integral roles in South Sydney's 2014 triumph and after McQueen moved to the Gold Coast to make way for the return of Sam Burgess 12 months ago, Keary parted ways with the Rabbitohs at the end of last season.

He didn't travel far, linking with long-time arch rivals the Roosters and McQueen believes a fresh start will help to rejuvenate the classy five-eighth.

Keary set up the Rabbitohs' first try in the 2014 decider and provided the last pass for Greg Inglis's try just before full-time and after playing 17 games last season McQueen is expecting the 25-year-old to have a significant influence on his new club.

"He's probably one of the most competitive blokes I've ever played with and he's a fiery little character too. Little angry man," McQueen told NRL.com.

"He's definitely one of the most competitive but he's got a good head for footy. He's probably got one of the best heads for footy.

"He can just read a game. He understands the game in a way that not a lot of people do.

"There's just something special about him."

With Pearce to play the role as the dominant half responsible for the organisation of the team, Keary will have the opportunity to bob up wherever his footballing instincts send him.

Combine that with a determination to re-establish himself as a quality NRL half and McQueen believes the Titans will have their hands full come Saturday night.

"When you go to a new club you find a bit of that hunger because it is a new challenge and new experience and it's refreshing as well because it is all new and different," said McQueen, who had three years playing alongside Keary at South Sydney.

"I'm expecting him to have that hunger and be at his best.

"If he's popping up all over the field that's going to make them a pretty dangerous side and it's going to make him a pretty dangerous individual."

There's something of a change for McQueen also in 2017 with the former Origin representative shifting from the right side to the left this season in order to accommodate the arrival of Kevin Proctor from Melbourne.

Many of McQueen's 116 games for the Rabbitohs were spent on the left side of the field and he says he and Kane Elgey have been working closely on their combination throughout the pre-season.

The Titans' left edge of McQueen, Elgey and centre Dan Sarginson will likely mark up against Aidan Guerra, Pearce and Blake Ferguson and McQueen knows that their defensive communication will be key in starting the season with a win.

"We've done plenty of work at training and obviously defence is the key to winning games of footy," said the 29-year-old.

"We've done a huge amount of defence in the break and we're all comfortable which how each other play and with our movements on the field.

"There's going to be no excuses if we go out there and don't get the job done.

"I don't think we're going to play our best game in Round 1 but we're still certainly going to show up and be competitive.

"We've done enough training to be able to go out there and put on our plays and get the job done."