Broncos halfback Tom Dearden.

Wendell Sailor insists 18-year-old debutant Tom Dearden showed up what is lacking in other members of the Brisbane Broncos side as he called on the players to show more mental toughness and desire.

Brisbane coach Anthony Seibold was the best man at Sailor's wedding and they remain close by that didn't stop the four-time premiership winner offering some pointed advice to the Broncos mentor and his team.

It is the qualities displayed by halfback Dearden on debut in the 38-6 loss to Souths that Sailor said needed to be replicated by the rest of the squad.

"We saw young Tom Dearden last week as an 18-year-old and I think he did a good job on debut. He took on Tevita Tatola early and went to the line, he kept competing and when Adam Reynolds scored that [intercept] try he kept chasing," Sailor said at a Magic Round promotion in Brisbane on Wednesday.

"They are the qualities I want to see in that side and I don't think we've seen enough of that this year.

"[Seibold] did a good job last year with Souths but as a person who watches and commentates on the game there is something amiss with the confidence and mental toughness of some of the players.

"When it is close, like against the Tigers, you have got to close those games out and I put that back on the experienced players like Anthony Milford and Darius Boyd. They should be leading the club there."

The 13th-placed Broncos will field three 19-year-old forwards against Manly at Suncorp Stadium on Friday night in Payne Haas, David Fifita and Thomas Flegler. Pat Carrigan is just 21 while Matt Lodge, Joe Ofahengaue and Tevita Pangai are 23, but Sailor said age was no excuse for where the Broncos found themselves on the ladder.

"I am disappointed with where they are placed," Sailor said.

"I know there are a lot of young players there but I think that when you are a young bloke on big money you've got to be willing to play at that level. Seibold has a youngish squad there but I don't like the fact that teams like the Roosters and Souths put points on them.

"It is hard to come in after a guy like Wayne Bennett and what they have had, but if you want the job that is part and parcel of it. I think Seibold will do the job but I am not going to say he needs time because I don't think he would be overly happy with where he is placed at the moment.

"They are only two wins outside the eight and we are all happy to sink the boot in, but the Panthers and the Broncos to me have underperformed."

Broncos legend Petero Civoniceva said the youthful Broncos would deliver for their coach but conceded the club was going through "a transition period".

"No doubt it's been a challenge for the group but I stand behind all these young players that are currently pulling on the Broncos jersey," Civoniceva said, also at the Magic Round promotion in Brisbane.

"I've got a good relationship with quite a few of the young forwards and in the past few months I've been in the background trying to be as positive as possible. When I made my debut, I was surrounded by Origin and international rugby league players who could help guide you through that process.

"These guys, they don't have that luxury so for us as ex-players, and there's quite a few of us now, we have full belief that we have something special there. It just takes its time to come to fruition.

"There's a lot of pressure on these young guys. There's always high expectations when you pull on a Broncos jersey. For these guys, it's about the process and being consistent and hopefully with a bit of luck we can turn things around and get the two points [against Manly] and build on that."

Former Brisbane coach Wayne Bennett was a pivotal influence on Sailor's career but he said his former mentor was thriving at South Sydney and understood why CEO Paul White pulled the trigger to sack him last year.

"For me as an outsider looking in it was frustrating reading the stories so I can understand. I don't know what started it – Whitey or Wayne. They were playing games in the media and as an ex-Bronco I didn't enjoy watching that so something had to give," Sailor said.

"Wayne is killing it at the moment but I don't know if he could have stayed here [at Brisbane] this year."