The 26-year-old was already signed on for next season, and is now locked into the club until just before his 31st birthday.
“I’m stoked to be staying at the club for a further three years and hopefully it’s another step in staying as a one-club player,” Johnston said.
“The last couple of years have been massive and I’ll be doing everything I can to ensure we go one step further than we did this year and win more premierships for this club.”
After debuting in 2014 and scoring a try in Souths’ drought-breaking title win that year, Johnston has been a fixture, mostly on the left wing, while also playing fullback at various points throughout his tenure.
He has topped the tryscoring charts in each of the last two NRL seasons, and is likely to pass club legend Nathan Merritt very soon as the man who has scored the most ever tries for the Rabbitohs.
Merritt crossed the stripe 146 times in his time at South Sydney, with Johnston currently at 136.
Given his age, fans and pundits alike have already started to murmur that Johnston could potentially eclipse Ken Irvine (212 tries) as the greatest in the history of the game.
If he continues playing on Souths’ potent left edge, he’s every chance.
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Johnston almost left the club last year, he said he was pleased to sort his future out so quickly this time around.
“I joked with ‘Ello’ [Souths head of football Mark Ellison] that I wanted to be the first to re-sign this time around and it’s great to have it all sorted out nice and early,” Johnston said.
The signing comes on the back of prop Mark Nicholls extending his contract last week, and will be music to the ears of fans – who were left stunned that Johnston was nearly allowed to leave the club.
The news will be some much-needed tonic for Souths fans after suffering a grand final defeat, and the departure of another local junior in Adam Reynolds.
“Alex is a tremendous finisher and is really building the other areas of wing play such as kick returns and defence,” Ellison said.
“He is a proud Indigenous man that rose to the Rabbitohs from La Perouse in the Souths Juniors competitions and has gone on to represent Australia, Papua New Guinea and the Indigenous All Stars so far in his career.”
“He is a popular member of the squad and is becoming one of the leading senior players at the club,” Ellison said.
“We’re very excited to be able to extend his contract for a further three years on top of his existing contract and look forward to seeing him score many more tries in that left corner in the years to come.”
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