Key forward duo Wade Graham and Matt Prior re-signed with Cronulla Sharks on Friday.
Graham, 26, has extended his contract for another two years, until the end of 2019, the NRL club announced.
Prior has agreed to a three-year extension, keeping him at the Sharks until at least the end of the 2020 campaign.
Sharks vice-captain Graham, who has played 182 NRL games, said: "Another two years, I'm really excited to get it done it's a good bit of security for my future."
Prior, the joint Sharks Player of the Year in last season's premiership campaign, has made 180 NRL appearances, having joined the Sharks from the St George Illawarra Dragons in 2014.
The 29-year-old said he was simply pleased to get his contract renewal out of the way.
"It's a massive relief and I'm glad it's done now. I can focus on footy and concentrate on the year," he told Sharks TV.
"Hopefully the rest of the boys stay and we can keep the good times going here at the Sharks."
The Sharks are seventh on the ladder after winning one of their first three games, and face the Parramatta Eels on Saturday.