Shane Flanagan is ready to throw his son into the NRL deep end in 2019.

He just won't let him drown.

The untimely walk-out of Valentine Holmes, the departures of Edrick Lee and Jesse Ramien to Newcastle and Ricky Leutele to the English Super League has left coach Flanagan down four backline players.

The Sharks have picked up former State of Origin and Test star Josh Morris from Canterbury to help fill a hole but the player drain also has Flanagan contemplating a move for playmaker Matt Moylan from five-eighth to fullback to replace NFL hopeful Holmes.

Such a scenario would almost certainly necessitate 20-year-old Kyle Flanagan stepping up to partner 2016 premiership-winning No.7 Chad Townsend in the halves.

The NRL's 2017 under-20s halfback of the year, Flanagan junior's class is abundantly evident after he scored a competition-record 344 points, including 19 tries that season.

His star continued to rise while helping pilot Newtown to the 2018 reserve grand final.

His father, though, has been reluctant to rush his progression, only handing the then-teenager a top-grade debut in Cronulla's round 24 thrashing of Newcastle in August.

But Flanagan might not have any choice but to use his son on a regular basis in 2019.

"He's definitely physically ready," Flanagan told AAP before the Sharks' first official pre-season training session on Monday.

"He played one game last year and had a really good season playing against men in the ISP (Intrust Super Cup reserve grade competition).

"He's just turned 20 years old and, pre-season, he's going to be about 90 kilos this year so he'll be right and ready to go, I hope.

"It's a big ask to play every game in the halves but, at some stage if he's going to be an NRL player, he's going to have to do it."

He's less vocal but, just like Ivan Clearly, Flanagan is excited about the chance to coach his son at NRL level - and reckons it'll be easier than some might think.

"I enjoy it. Sometimes the communication we have is a lot easier than with a lot of the other players," he said.

"Sometimes I don't have to say too much. He understands what's gone good or what's gone bad.

"So it makes easier."