Penrith have locked in the final piece of their NRL premiership puzzle with star five-eighth Jarome Luai re-committing to the club for the next three seasons.

The 24-year-old has put pen to paper with the Panthers just two days after the club confirmed rising star Stephen Crichton had also agreed terms with the grand finalists.

Luai's re-signing opens a premiership window for the Panthers after the club locked in a slew of breakout stars who have climbed the junior ranks together.

In keeping the group together, Penrith were forced to release Josh Mansour, James Tamou and Zane Tetevano for 2021 to clear the salary-cap space.

Their 17-game undefeated run to last year's grand final was largely attributed to Luai's combination with halfback Nathan Cleary, a partnership now set to continue until at least the end of 2024.

"I first watched Jarome playing alongside Nathan (Cleary) as a 15-year-old," Panthers coach Ivan Cleary said.

"He had to wait a little bit longer to cement his spot in the NRL but the natural combination those two have will be vital for our club over the coming years.

"Jarome's value to our team is more than just his individual skills.

"He has an ability to connect the players around him, which is crucial to our success."

Luai is the final big name the Panthers were desperate to lock in after Crichton and co-captain Isaah Yeo also re-signed beyond the end of the season.

The Panthers are set to play Parramatta in the final trial of the NRL pre-season on Saturday before taking on North Queensland in round one on March 13.