Teenage prodigy Haas justified the hype that has swirled around him for years with an impressive NRL debut in Thursday's 24-20 defeat of South Sydney.

The rugby league world was in awe of the fact the 194cm, 117kg giant is still only 18 after he took his opportunity with both hands against the Rabbitohs.

Wayne Bennett and the Broncos have been careful to manage the highly-touted Newcastle product ahead of his highly anticipated debut.

And Haas was asked to do a big job for the Broncos after they were effectively reduced to a two-man interchange after Josh McGuire suffered an ankle injury and Lodge was pulled after just 23 minutes and left on the bench for the rest of the game.

"You've got to get your kids ready at some stage and start the process," Bennett said.

"Obviously Payne's going to be an NRL player for a long period of time.

"It's just getting him into the game and how you do that and try and manage that. Because I don't want them to get ahead of themselves. At the same time I want him to be able to handle the situation as well.

"He's been in the state league for a while and he'll probably spend a few weeks on the interchange bench and maybe then we'll make another decision."

Asked about his decision to leave Lodge on the bench for three-quarters of the game, Bennett said: "Matt was just off his game tonight."

In just 21 minutes of game time, Haas ran for 86 metres.

However, most impressive was his effort on a key kick-chase which saw him collar Richie Kennar and trap him in-goal.

The play gave the Broncos field position and led to James Roberts crossing for what proved to be the match-winning try.

"That was a big effort and a big play from a big boy on debut," Broncos teammate Kodi Nikorima said.

"He's still a young bloke and he's doing a lot to learn.

"But what he did well tonight is he ran hard and he tackled hard. That's all you can ask of a young prop coming into the team."

Nikorima revealed Haas was showing signs of butterflies in his stomach prior to kick-off.

"Before the game started I told him 'go out there and have some fun, it's just another game'. He told me he was a bit nervous before the game. I tried to calm him down," Nikorima said.

Australian Associated Press