The Warriors-bound halfback received the news earlier this week which has come as a terrible blow to the Sharks' finals chances as they prepare to face Manly on Sunday.

It's the second year in a row Johnson's season has been cut short with a leg injury after he ruptured his Achilles tendon while the Sharks were in a battle to make finals in 2020.

Ironically, he also suffered last year's injury in round 19.

The recovery from that Achilles injury kept him sidelined until round seven this season, but heads dropped when he was helped from the field in a victory against Canterbury last weekend.

Cruelly, it was the last time he will appear in the Sharks jersey before returning to the Warriors next year.

"Shaun's really disappointed and we're all disappointed for him," said Sharks coach Josh Hannay on Friday.

"A tragic sort of injury, really, it's season-ending for sure, it's his last game for the club.

"It's not the way he wanted to end his time at the club and it's another reminder that you don't get the fairytale ending.

"It's a sombre mood for a couple of days there earlier in the week when we realised that was his fate.

"Shaun was clearly devastated when he got that news."

The 30-year-old has already started the rehab process.

Hannay said the club and Johnson are now working through whether he will stay with the team in their hub in Queensland or return to Sydney with his young family.

"That's the next step now, we're in the process of having those discussions with Shaun and obviously Shaun will be having discussions behind the scene with his family," Hannay said.

Without Johnson the Sharks lost their last two games of the season last year to bow out of week one of the finals with a 32-20 loss to Canberra.

They're currently seventh on the ladder with six games to play and a reasonable draw, but face the red-hot Sea Eagles on Sunday as well as fellow finals hopefuls Newcastle in round 22 before ladder-leaders Melbourne in the last round.

Matt Moylan is also sidelined with injury and will miss Sunday's clash, although he is expected to return to face the Warriors next weekend.

It leaves the rookie halves combination of Connor Tracey and Braydon Trindall to steer the ship.

"It's not ideal. One of the real keys to performance and success in a situation where you're vying for the eight, you want to be as healthy as possible," Hannay said.

"That's just a reality. At the moment losing Shaun just adds to Matt Moylan being out at the moment, young Teig Wilton being unavailable too.

"But the one thing I'll say is I'm really happy with the way Braydon Trindall has stepped up."

Australian Associated Press