Cronulla are sweating on star playmaker Nicho Hynes making a quick recovery from a quad strain that has ruled him out of Sunday's NRL clash with Newcastle.
The Dally M Medallist suffered the injury at training and will miss the trip north for the sold-out McDonald Jones Stadium match.
It's a massive blow to Cronulla's top-four hopes as they sit two points behind fourth-placed Melbourne, who host Gold Coast on Saturday.
Just one competition point separates the fifth-placed Sharks and seventh-placed Knights on the ladder.
Hynes missed the opening three games of the season after suffering a calf tear in pre-season with Cronulla losing two of those matches, so his team will be hopeful he can return to face Canberra in the final round.
The Sharks have been on a roll of late, thumping South Sydney, Gold Coast and North Queensland over the past three rounds.
Veteran Matt Moylan is now expected to partner Braydon Trindall in the halves.