Cronulla Sharks captain Paul Gallen has praised the work of interim coach John Morris and the decision of Shane Flanagan to "fall on his sword" for the sake of his club by resigning from the head coach role.

Flanagan officially resigned on Monday after being deregistered by the NRL late last year for breaching the terms of his 2014 suspension over the club's peptides regime. Morris has been coaching the side since then and is one of the contenders to replace Flanagan full-time.

Gallen said the entire club had been in shock with the initial decision to de-register Flanagan but that the premiership-winning mentor had done the right thing by the club by moving on.

"I did speak to him [on Monday] after the decision was made," Gallen told Triple M's Rush Hour with MG.

"Look I've got to hand it to him to be honest. It's been a tough time for him, and once again he has put the boys and the club first. He's fallen on his sword and he's left to allow the club to move forward.

"Now obviously the club and himself have come up with an arrangement moving forward, and I've got no idea what that is, to adopt a mutual agreement to separate which allows the club and Flanno to move forward.

"So I think it's a good result for all parties."

Flanagan resigns

Former Sharks players Cameron Ciraldo and Trent Barrett are two players with NRL coaching experience in 2018 who would be candidates for the Cronulla role, but Gallen said he couldn't fault Morris's work with the team so far.

"That's going to be a decision – and I suppose it'll be spoken about pretty regularly for the next couple weeks –  and obviously the board will make a decision on that going forward," he said.

"But I've got to give 'Bomber' [Morris] a lot of credit so far, he's been really, really good. He hasn't missed a beat at training. The attitude of the players has been really good and the attitude of Johnny Morris has been great.

"He's very organised, very diligent in his work, and things have been really good.

"For the time being things are great and obviously in the next couple of weeks we'll get named not just an interim coach but a head coach for the rest of the season."

Flanagan is the second big name the club has been forced to replace ahead of the 2019 season, with Kiwis superstar Shaun Johnson having arrive in place of NFL-bound fullback Valentine Holmes.

"He's been great," Gallen said of Johnson. "Obviously the Valentine Holmes situation was disappointing for the club, it was hard.

"But to pick up a player like Shaun Johnson, the timing was unbelievable – it couldn't have happened any better.

"I was shocked that the Warriors allowed him to leave, and the way he left the Warriors was a little bit sad also. He's the face of New Zealand rugby league.

"But he's slotted right in really well and he's going to be a major part of our year."