Fast-forward a few months, and South Sydney's left winger is now setting himself the goal to enter the history books this year.
Johnston crossed for four tries in Saturday night's 25-24 golden-point loss to Melbourne, three on the back of Latrell Mitchell passes and one from an intercept.
The haul moved Johnston onto 206 tries for his 234-game NRL career, only six behind Ken Irvine's benchmark of 212 that has stood since 1973.
"If you told me a few weeks ago, it was still a fair bit away, but I've scored a few tries the last few games and gotten pretty close now," Johnston said.
The coveted milestone seemed a world away for Johnston after he was assisted from the field with an Achilles injury in a big loss to Canberra last July.
Even as he locked into his recovery, there was no guarantee the then-29-year-old would return to the field at his best - or at all.
Achilles injuries can curtail a player's speed - a vital tool of the trade as a winger - and Johnston was coming into the last year of his Souths contract in 2025.
It began to cross Johnston's mind that he may not ever reach the record for which he had long been touted.
"It did a fair bit. I don't want to harp on it too much," he said.
"I was probably not in the best place for a good while there.
"I was pretty lucky, I've got a pretty good rock at home, my family are always there for me.
"To be 206 now, I'll just keep ticking them over. Things are turning around, looking up."
The milestone moment could come in a matter of weeks if Johnston keeps up his current rate of 11 tries from seven games this year.
There's a little less urgency now, though, with negotiations for a contract extension reaching their advanced stages.
"We believe that will happen but it hasn't happened yet. There's a bit more negotiations to be done," said Souths coach Wayne Bennett.
But regardless, Johnston is starting to believe he can break the record before 2025 is up.
"l'll try my best to get it this year and hopefully just keep doing my job for the team," he said.
"Obviously it'll be very special."