Such is Nathan Peats' competitive and combative nature, his arrival at the Gold Coast Titans midway through the 2016 season came with a warning label.
"I tipped the boys up pretty quick that he's a bit moody and he's fiery," said Chris McQueen, who spent three years playing alongside Peats at the Rabbitohs from 2011-2013.
Peats is an intense and complex character who combines a cutting sense of humour that is most brutal to those closest to him with a borderline obsessive compulsive disorder that requires he completes every training session performing the same drill with the same coach.
Every time.
"He's pretty particular," adds McQueen.
"I've seen on occasion if something doesn't go right in a set of six, instead of just carrying on and getting through the set, he'll just stop and walk off.
"I've seen him walk off the field and let somebody else come on.
"When things don't go his way he certainly fires up but all the boys know to take that with a grain of salt and have a laugh.
"They know when to push his buttons and when to leave him alone."
His reputation is that of the ultimate competitor but for all the grief he may cause coaches and teammates, Peats is also a proven winner.
In seven seasons in the top grade the teams in which Peats has played for have had a losing record only once in games in which the 26-year-old No.9 has featured, and these have not been high performing teams.
After captaining South Sydney's under-20s team that qualified for the grand final in 2010, Peats graduated to the Rabbitohs' NRL team in 2011 with the team winning 10 of the 20 games in which he was in the team. They won only one of the four that he missed to finish 10th, one win outside the top eight.
He played 18 games in 2012 and South Sydney won 10 on their way to a third-place finish and a year later the Rabbitohs won 13 of the 17 games that Peats played.
In 2014 he moved from the Rabbitohs to the Eels and won six of the 10 games that he played in an injury-riddled start for his new club who could manage to record just six wins in the 14 games that he missed to miss the finals on points differential.
The only losing season of his career to date came in 2015 as the Eels narrowly missed finishing with the wooden spoon but then in 2016 he finished with 11 wins from 20 games for the Eels (4-2) and Titans (7-7).
Forced to do without their No.1 hooker for the first six games of the season this year the Titans could conjure just the one victory but won three from four upon his return to reignite their finals hopes.
His absence last week against the Cowboys was obvious but after recovering from his corked quad in Origin I – where he has a 100 per cent winning record for the Blues – Peats is due to return for the crucial clash with the Warriors on Saturday.
Playing through the pain to punch out 80 gut-busting minutes for New South Wales last Wednesday, McQueen expects to see Peats take his game to an even higher level having performed so well in his Origin debut.
"He is a senior player and he's not shy to speak up when something needs to be said but when you start playing Origin and get a bit more experience, whether you want it or not, you get that leadership role," said McQueen, who played six Origins for Queensland.
"Although everyone already looks up to him I think people will be looking for more out of him.
"If anything he'll come back a better player, if that's possible. He's a great player and one of the most professional players I've ever played with, one of the most competitive players so I really don't think there's a lot for him to learn. Maybe he'll get a bit more confidence but he doesn't lack that either.
"For me the most important thing for us as a team and for him is to come back and keep doing what's he's been doing because what he's been doing for us all year and for his whole career really has been great."
Titans coach Neil Henry knew that last Saturday's assignment in Townsville was going to be all that much tougher without Peats taking the team forward out of dummy-half and controlling the ruck and also expects a more complete player to return to club-land.
"He's proven he can match it on that arena and is playing against very good players," Henry said.
"Hopefully that's a positive spin. He's got a bit more self-belief because he's competed at that level.
"He can bring that back in a positive light to his club footy."