Broncos youngster David Fifita.

Generational change at Brisbane has presented new coach Anthony Seibold with a question that should be answered by the end of round four.

The Broncos were always going to field a young pack short on NRL experience after the off-season exits of Sam Thaiday, Korbin Sims and Josh McGuire - a trio collectively boasting more than 600 games in the top grade.

The early pre-season training and match form of 18-year-old back-rower David Fifita, 21-year-old lock Pat Carrigan and 19-year-old prop Thomas Flegler has given Seibold a welcome selection headache in one sense, but a tough decision to make in another.

That has been compounded by the four-game suspension of 19-year-old prop Payne Haas for failing to co-operate fully with the NRL Integrity Unit over an investigation into an incident involving his family.

Haas was almost certain to be in the top 17 for round one but now won't be available until the round-five clash with the Wests Tigers.

His absence aside, the Broncos are entering a phase where their best and brightest forwards do not have hard-headed club legends to guide them through their formative years.

When Shane Webcke and Brad Thorn came on the scene they had the likes of hardened premiership winners  Andrew Gee, Peter Ryan and Gavin Allen to learn their craft.

Youthful 2006 title-winners Corey Parker and Sam Thaiday were mentored in turn by Webcke, Thorn and Petero Civoniceva, and by Gorden Tallis in the preceding seasons.

Former coach Wayne Bennett was able to ease the newcomers into the top grade with a bevy of proven champions around them.

The advice and example of Broncos veterans Matt Gillett and Alex Glenn will be valuable assets this season, but the current crop of young middle forwards in particular will not have leaders of the stature of the premiership-winning Broncos of the past to feed off on the field.

It will be sink or swim, particularly in the opening four rounds when the more experienced packs of Melbourne, North Queensland, St George Illawarra and the Sydney Roosters will be certain to apply the blowtorch.

On form, and on the potential carnage he could cause, it will be hard for Seibold to leave edge forward Fifita [11 NRL games] out of his 17-man squad to play Melbourne in round one. Carrigan and Flegler, yet to make their debuts, will also be in the frame.

Just how many unproven and inexperienced forwards will Seibold field at once, and will they be up to the challenge?

The answer is not easily forthcoming when you consider Tevita Pangai jnr has started in just 18 of his 54 NRL games, Matt Lodge in 24 of 37 games and Joe Ofahengaue in just 12 of his 70 matches.

Broncos forward Tevita Pangai jnr.
Broncos forward Tevita Pangai jnr. ©Jason O'Brien/NRL Photos

That trio will be expected to lead the way up front this year but all are still relative newcomers in comparison to the forward opponents waiting for them in the first month. You can be sure that Jesse Bromwich, Matt Scott, Tyson Frizell and Jared Waerea-Hargreaves – just to name a few – will be keen to test their mettle.

The Broncos are entering the unknown. Seibold and his staff have been working overtime to get the young brigade ready but only the weekly grind of the NRL will reveal whether they truly are. It will be a baptism of fire, which is why there are opportunities for the more experienced Shaun Fensom and 2016 premiership winner Sam Tagataese to make a statement in the coming weeks.

Both will play the trial against Wynnum-Manly on Saturday night and Seibold wants the pair to be challenging for a top-17 berth, for their own sake and to give him genuine options.

Fensom is "very excited" to make his Brisbane debut and he said he was determined to prove to Seibold that he was worthy of a bench spot at least.

"I have had a strong back end of this pre-season so I will be looking to go out there to put my best foot forward to secure a spot," Fensom said.

If he does it will make Seibold's night.

Seibold doesn’t have three Burgess brothers with more than 550 games of NRL and Super League experience as middle forwards in his side this year.

What he does have is a posse of the most naturally gifted young forwards ever seen at Red Hill at once, and with that will come challenges.