Sharks winger Sione Katoa.

Sharks speedster Katoa skips straight into NRL

Twenty-year-old rookie Sione Katoa is being touted as one of the quickest players in recent Cronulla Sharks history, and his rapid rise to first grade is mirroring the youngster's scintillating speed out wide.

Katoa will line up for his Telstra Premiership debut against the North Queensland Cowboys on Friday in his first senior football outing, having graduated straight from under 20s into the top flight and bypassing the traditional InTrust Super Cup stint used to groom most young players.

Sharks insiders are talking up the churchmouse-quiet winger as one of the fastest seen during Shane Flanagan's eight-year tenure at the club, and Katoa was clocked at an eye-watering 9.69 metres per second in pre-season training.

In just his second season of under 20s last year Katoa rattled up a competition-best 24 tries for the year, and as aresult has pipped more senior counterparts in Aaron Gray and Edrick Lee for a spot on Cronulla's right wing.

"He deserves his spot, he's played well in the trials coming off the back of the under 20s season last year," Flanagan said.

"He's going to score a lot of tries in the NRL, he's a superstar."

Treading the same path as Sharks skipper Paul Gallen, Katoa was originally a Parramatta Eels junior before moving to the Sutherland Shire in 2016.

As softly spoken as they come, the Kiwi flyer sat out the club's recent all-in media day but already has Flanagan talking a big game, with the Cronulla coach comparing him to Katoa's compatriot, Canberra Raiders wrecking ball Jordan Rapana.

"He's got a bit of Jordan Rapana in the way he carries the football," Flanagan said of Katoa, who tips the scales at 88kg.

"He's not as big as Jordan, nowhere near that but stopping and starting, reloading and just keeping going until he finds a hole.

"It's really exciting to get to watch him play and give him his first jersey. It's the start of a long career."

Katoa will line up outside marquee signing and right centre Josh Dugan against the Cowboys.

While Valentine Holmes will get first crack as Cronulla custodian, Flanagan revealed Dugan had been helping coach Holmes in the position he has long coveted for himself.

Debate around Dugan's best position, and whether he should earn fullback or three-quarter dollars as a result, coloured much of his 2017 season before linking with Cronulla as the "world-class player" he felt arch-rivals St. George Illawarra Dragons did not recognise.

Dugan and fellow star recruit Matt Moylan have foregone their favoured fullback roles in moving to the Sharks, but Flanagan is seeing an upside to Holmes's development at the back as a result.

"Especially with Josh Dugan coming into the squad, Josh has helped [Holmes] a lot," Flanagan said.

"We all know that he and Matty can play both play there if required. But Josh has been a real support for Val the last couple of months and some of the tips that Josh is passing down to Val are going to be valuable as he develops as a fullback."