The setback of the 32-Test New Zealand international has dealt the Sharks' finals hopes a mega blow, with seventh-placed Cronulla one of seven clubs jostling for the last two positions in the top eight ahead of the remaining six rounds.
If Johnson's recovery from the injury goes horribly wrong he might not play another game with the Sharks, with the veteran set to return to the Warriors on a two-year deal after this season.
Johnson strained his hamstring as he skipped with the footy on the right edge in the 33rd minute of the Bulldogs clash.
While the passage of play ended in fullback Will Kennedy icing a long-range Cronulla try, it also resulted in Johnson limping off the field immediately and never returning.
Eels legend Peter Sterling said Johnson looked "distressed" as he left the field, but the Sharks playmaker was defiant in an interview with Nine.
"We'll look after it as best I can and hopefully it's not too long (until I'm back on the field)," Johnson said.
"This isn't the way I want to go out in a Sharks jumper. I want to finish off the year strong with these boys playing footy games. I'll do my best to get back out there and hopefully the boys can keep rolling."
Johnson's latest injury blow follows the rupture of his right Achilles in Round 19 of last season, which sidelined him until Round Seven of his 2021 campaign.
The 30-year-old also suffered a strain to his left hamstring earlier this season, which ruled him out of Magic Round and Round 11.
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