Brisbane Broncos head coach Anthony Seibold felt critics were leaping at the opportunity to take a cheap dig at his side following their worst start to an NRL season this century.

The Broncos were edged out 26-22 at Canberra Raiders on Sunday, falling to their fifth defeat from the opening six matches of the campaign.

Not since 1999 have Brisbane endured such a torrid run to begin the year, their latest reverse at GIO Stadium leaving them as one of only three sides in the ladder on two points after half a dozen rounds.

The off-season saw Seibold swap roles with Wayne Bennett, who has guided South Sydney Rabbitohs to five wins from six, but the Broncos coach remained defiant in the defence of his inexperienced squad.

"We've had a really challenging start with Melbourne [Storm] and [Sydney] Roosters and some in-form teams," said Seibold.

"Three of the last four games we've been there or there abouts right at the death. When they don't go your way, you are very disappointed but for me it's really important to be composed and look at the bigger picture.

"The club has gone in a specific direction. If you look at the players who are not here this year who were there last year; Josh McGuire, Sam Thaiday, Jordan Kahu — they're all internationals.

"We had five players under 21 playing through our middle [on Sunday]. The Raiders have won five from six and I don't think our younger players looked out of their depth.

"There is no other team in the competition with three 19-year-olds playing through the middle at the back end of the game and they weren't out of their depth.

"I'm going to back the young players and back our team. We're a shandy away. Two of the last three games we lost it literally with the last play of the game, so we're not a million miles away.

"When you're going through tough times that's when you see who is really a rusted-on supporter and who is dedicated to the cause. This is an easy time for people to have a free shot at the Broncos."