The Dolphins will host their first preliminary final at Suncorp Stadium next weekend, with a maiden NRL grand-final appearance at stake.
They have also secured an important part of their future, extending utility Brad Schneider's contract for two seasons through the end of 2028.
Schneider, 25, had remained off contract for 2027 throughout the 2026 season.
He joined the Dolphins from Penrith this season and has made 13 NRL appearances, supplying cover across the spine and backline.
His retention follows Kodi Nikorima's decision to join the Dragons at season's end.
That departure will create a permanent halves opportunity beside Isaiya Katoa, with Schneider competing against incoming English international George Williams.
Williams will join Kristian Woolf's squad during the off-season.
Dolphins chief executive Terry Reader said Schneider and outside back Tevita Naufahu, who signed through 2029 this week, were important long-term additions.
"Brad has been a great addition to the squad and has shown his value every time he has taken the field," Reader said.
"He has provided us with quality and depth in the halves and has made a real impact in his first season at the club."
The Dolphins' preliminary-final opponent will be the winner of the Roosters-Sharks semi-final.