Broncos centre James Roberts.

Broncos captain Darius Boyd has hailed the transformation of James Roberts into a genuine leader at the club as the representative centre continues to fire despite carrying a nagging Achilles injury.

Boyd said Roberts' defensive work against Roosters counterpart Latrell Mitchell last week "went a long way to getting us the win" and pinpointed that area of improvement along with his ability to play through injury as key indicators of his growth.

"A couple of years ago if James was going through what he is now with his Achilles he probably would have missed a few games or gone through the motions, but this year he has been one of our better leaders,” Boyd told NRL.com.

"When James came here he had an attacking mindset and with his attributes it was a no-brainer for him to think that way, but sometimes the ball doesn’t come to you in the centres.

“While we have spoken about getting him more ball James has taken it upon himself, if he doesn’t get it, to go looking for it.

"He also knows he can do the job in defence and that is where he has made massive strides and is why he got picked for NSW this year."

Roberts has an inflamed left Achilles tendon which he is managing. He confirmed on Wednesday that it was not really improving, but added that he was over any post-Origin fatigue.

"I am just coming good now,” he said ahead of Sunday's showdown with Manly at Suncorp Stadium.

"Mentally I think [Origin] is very draining, and physically. I am feeling a lot better than I was three weeks ago.

“[The Achilles] is not really getting better. It is pretty much the same really. I’ve got to keep managing it and loosening up my calves, but I’ll be right.

"Rest is good, but we don’t really have any time to rest at the moment. It is about getting the job done."

Roberts said that while he would relish having the ball in hands more, he was more than ready to do his job defensively.

"My main focus is defence at the moment but if I do get the ball at the right times I am confident I can do the job,'' he said.

 "Ideally I want the ball as much as possible but if we are in a grinding game it is what it is. You’ve just got to make your tackles and take the tough carries."

It is that maturity in Roberts approach on the field that Boyd said had flowed from his work off it.

"I just think he has really matured, his life outside of rugby league is a lot more settled than what it was and he’s been working on himself personally off the field," Boyd said.

"He talks more on the field, where he is more of a leader and sees himself as a leader. James had a great start to the year and being picked in the NSW Origin team not only gave him a lot of confidence to know that he belongs in the NRL but also is one of the better players in the game.

"You go to a promotional thing now or anywhere around the fans and they say ‘there’s Jimmy the Jet’.

"They just want to see Jimmy the Jet which is great for the game but the best thing is that what he done off the field he is bringing onto it, to be the best player he can and really lead by example."

Roberts is not finished yet and was in a bullish mood was asked whether the Broncos could maintain momentum for four consecutive finals to win the competition.

"I think we can win the whole thing but it comes down to being ‘on’ on the day and doing our job individually for the team,” he said.

"I am pretty sure they write us off every year but we know what we’ve got to do and we are all confident in each other."

One man who won't be playing in the finals series is 2016 premiership winner Jack Bird, whose sternum injury has not improved enough for him to play this season.

Roberts said Bird would be back to his best next year after more rest and recovery in the off-season.

"Birdy's had a bad run with injuries and he didn't come to us 100 per cent but he will be ready to go once he gets a good pre-season under his belt," he said.