Generally, the conversion rate of talent from rugby union juniors to seniors and onto the Wallabies is pretty good.

With so many pathways and such elite talent development systems, it is not often such top-level talent get missed, or passed over on.

However, every once in a while, one will slip through the cracks, or opt for a career in another sport as opposed to the game they play in heaven – usually, opting to the life of league as opposed to union.

Who are those guys that make you wish your state had not missed out on them? Who are the most prodigious rugby league talents that once were future stars in the 15-a-side code?

Josh Hoffman, Gold Coast Titans

Born and raised in Mackay to a Maori father, Josh Hoffman qualifies for both Australia and New Zealand, and given his fathers' nation of origin, it is no surprise Hoffman played a little bit of union growing up.

In his NRL career, the 27 year-old has played 134 matches for both Brisbane and Gold Coast, scoring 39 tries. He has also been capped for New Zealand five times, which speaks of his extraordinary talent.

Hoffman played as an inside centre in his youth union days, and was not long ago linked to a deal with the Queensland Reds. He is also related to former Wallaby and Brisbane Bronco Wendell Sailor.

Semi Radradra, Parramatta Eels

Semi Radradra featured in both the 2011 World Rugby Junior Championships, as well as the revered Fijian sevens side, yet was signed by the Parramatta Eels in 2011.

The moved proved to pay off in a big way – Radradra has scored 48 tries in 50 matches with Parramatta, has been named the Dally M winger twice in a row and has broken the Eels' single-season try-scoring record, scoring 24 in 2015.

Given how close New Zealand and Australia are to Fiji, it's surprising union clubs from both nations missed out on signing the ‘Semi-Trailer'. Similar to the road Henry Speight has taken to the Wallabies, Semi Radradra could now be an internationally capped winger.

Curtis Rona, Canterbury-Bankstown Bulldogs

Curtis Rona is one of the causalities of the Western Force's academy being shut down – after moving from New Zealand to Perth, Rona took up union, and after the Super Rugby side's academy shut its' doors, he took up league.
Since then, the 23 year-old has proved himself as a very capable young NRL level winger, playing 33 matches for the Cowboys and Bulldogs and scoring 31 tries.

Rona was also included in the 25-man New Zealand squad to tour England at the end of last year. Considering he could instead have been included in a Rugby World Cup squad for Australia by now, it's a bit of a kick to the guts, especially for the struggling Force.

Elijah Taylor, Penrith Panthers

Elijah Taylor is a more peculiar case than most on this list – he didn't go through just one Ranfury Shield side in his native New Zealand – he went through three.

Taylor played in different age groups at Taranaki, Northland and Auckland before finding his way to rugby league at age 16. Since then, he has papered over 100 times for the New Zealand Warriors and Penrith Panthers.

Taylor has also appeared on 10 occasions for New Zealand, most notably during the 2013 World Cup. Given his similar skill, size, frame and playing style to his idol Sonny Bill Williams, could Elijah Taylor have been an All Black by now?

Jason Nightingale, St. George/Illawrra Dragons

As a youngster, Jason Nightingale lived in Waikato – the most obvious catchment area for the famous Waikato Chiefs. However, after moving to Sydney, he took up rugby league, and the rest is history.

It's obvious where Nightingale gets his play style. Whilst he doesn't have the speed and quickness of most league wingers, he is strong, safe on defence, and as consistent as any in his position.

His excellence at his position is magnified by his nearly 200 games for the Dragons, and 27 selections for New Zealand. If he'd stayed in Waikato, it's not hard to imagine those stats would be union ones.

Roger Tuivasa-Sheck, New Zealand Warriors

As a teenager, Roger Tuivasa-Sheck played both codes at Otahuhu College, and excelled at both – he played for the NZ schoolboys union team and captained his school in league.

Evidently, the Sydney Roosters got to RTS first, and now one of the great young talents the game has seen in a long time is committed to league.

At just age 22, Tuivasa-Sheck has already played 85 times in first grade, and 11 times for New Zealand, scoring 9 tries. It's scary to think that the mammoth future he's destined for was almost one in union, almost certainly with the All Blacks.

Tohu Harris, Melbourne Storm

Hastings Boys High School has so far produced seven All Blacks, and that may have been eight if Tohu Harris had've stuck at union.

Instead, the Melbourne Storm signed Harris, and his inevitable international rugby career has been carved out in the NRL. So far, at age 24, he has made 77 club appearances and 10 for New Zealand.

Without overstating anything, Harris' size, frame and skillset are not dissimilar to a young Richie McCaw. If his local Wellington Hurricanes had signed him, maybe Harris would've played alongside him by now – or at least against him.

Mitchell Pearce, Sydney Roosters

League runs in Mitchell Pearce's veins – his father Wayne is a legend with the Wests Tigers in the NRL, which makes it difficult to believe he could have been playing union.

Before transferring to Marist College North Shore, where he played league with his friend Kieran Foran, Mitchell Pearce was plying his trade in the other game for Barker College.

Whilst not as famous a rugby school as some other institutions in that area, if Pearce had've been noticed playing in the NSW schoolboy rugby competition that so many other Wallabies have been plucked from, it's likely he would've earned a contract with Super Rugby side.

Shaun Johnson, New Zealand Warriors

Shaun Johnson played many sports at high school – basketball, touch football, even Australian rules, and of course, rugby.

However, from Johnson's own mouth, it was an “unsatisfying” stint in the Orewa College first xv that pushed Johnson to rugby league.

After 102 games for the Warriors, 14 caps for New Zealand, one Four Nations and one Golden Boot, and it's fair to say there are plenty around the world glad that Johnson is not playing against their nation in rugby union.

Cooper Cronk, Melbourne Storm

Cooper Cronk is widely considered one of the greatest rugby league players of all time with 27 matches for Australia, 15 for Queensland, almost 300 for the Melbourne Storm and numerous Dally M awards.

Yet as a teenager growing up in Brisbane, Cronk was fixated on the other code, playing in the first XV at St. Laurence's for a number of years.

Despite ample years of his talent on display to his local Queensland Reds, he was signed by the Melbourne Storm, and went on to greatness with the historic club.

Would we have loved to have seen Cronk in the green and gold of the Wallabies? You bet.