Cameron Ciraldo is certain teenage rookie Karl Oloapu is ready for first grade after handing the playmaker an NRL debut on Canterbury's bench against St George Illawarra.

Ciraldo confirmed on Saturday morning the highly-talented teenager would face St George Illawarra, coming onto the Bulldogs' bench with Max King out injured.

At 18 years and 102 days, Oloapu will become the youngest player to feature in the NRL this year after a summer of hype around the half.

A former Australian schoolboys captain, Oloapu was a star of Brisbane's junior system from age 13 until a messy split with the club late last year when he refused to continue training.

Such was Canterbury's desire to land him as a long-term playmaker on a four-year deal, they paid a transfer fee of $500,000 to Broncos to bring him down to Sydney.

"Karl is a guy we think has a big future at the Bulldogs, and we're excited to start the journey tomorrow," Ciraldo said on Saturday.

"He is ready. He has been ready for a number of weeks now.

"He didn't have his best game in reserve grade last week, but he has shown us more than enough over the first eight weeks of NSW Cup and in training that he is ready to take his shot.

Ciraldo said Oloapu had become emotional when told of his looming debut on Thursday, but otherwise handled the week well.

The Bulldogs have named veteran Josh Reynolds to start in the halves alongside Matt Burton for Sunday's clash with the Dragons in Wollongong.

But it appears only a matter of time until they roll out their long-term combination of Oloapu and Burton.

Kyle Flanagan is seemingly on the outer at Belmore after being dropped to reserve grade, while Reynolds is likely only a stop-gap measure.

In Oloapu and Burton, the Dogs have two playmakers aged under 24 on long-term deals.

"He will come off the bench tomorrow but we have a plan for him moving forward," Ciraldo said of Oloapu.

"We don't want to worry about that tomorrow. We want him to go out tomorrow, enjoy his debut; you only get to do that once.

"Just focus on playing his own style of game. And as a team, we need to support him."

Ciraldo also confirmed that prop King had been playing with a fractured sternum and rib since part way through their round-seven loss to Parramatta, before being sidelined this week.

He is expected to miss around a month.

"He has played two weeks with that fracture. It shows the toughness of the guy and his character," Ciraldo said.