Hynes was sidelined inside just two minutes on Saturday night, getting his head in the wrong spot while tackling Salesi Foketi in Cronulla's 46-10 defeat.
On a brutal night for the Sharks, centre Mawene Hiroti also injured his knee after he clattered into the Allianz Stadium advertising hoardings while keeping a ball in play.
The injuries cruelled Cronulla, who played 60 minutes with just two active men on the bench as the Roosters ran in five second-half tries.
But as seems forever the case the bigger question for the Sharks is how they take the next step from here.
Only one other team in the NRL era has played five or more finals series without reaching a decider.
And that is the current Roosters, who can go all the way to the final Sunday of the season if they beat the Dolphins at Suncorp Stadium next Friday night.Â
Cronulla have now played finals in nine of 10 seasons since their maiden 2016 premiership, but never returned to the decider.
Since Craig Fitzgibbon took over in 2022, the Sharks have made finals every year and had one of the most stable rosters in the competition.
In every season but one they have been knocked out in week two or week three of the finals, unable to go from contender to powerhouse.
Fitzgibbon has stressed in recent weeks this is not the end of an era, despite Cameron McInnes, Sione Katoa, Sioisifa Talakai and Hiroti all leaving the club.
For parts of this season this Sharks outfit had looked the team to go to the next level.
They were the best team in the NRL through the middle third of the year, with that run of form headlined by a 66-0 flogging of the Dolphins in Redcliffe.
But the wheels fell off in the final month of the regular season with Braydon Trindall dislocating his shoulder and losses to four separate bottom-eight teams.
Ultimately, on Saturday, injuries again didn't help with Niwhai Hiroti thrust into the halves after Hynes's injury.
Hiroti's knee blow had the potential to be heroic, given Cronulla scored twice more without the Roosters touching the ball after the centre's effort to keep it in play.
But once Cronulla got it back to 12-10 down, it was the Roosters who had the class and finish in the second half.
The slick hands and skill of Mark Nawaqanitawase was on show for all to see, while Robert Toia, Siua Wong and James Tedesco also excelled.
Cronulla, meanwhile, couldn't ice their chances.
While two Trindall kicks were caught in goal early in the first half, the five-eighth didn't stop trying though he spilled a chance over the line when Cronulla trailed by 14 with 20 minutes left.
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