The Kiwis pair have been confirmed to start in the halves for Saturday's clash with the Dragons on the Sunshine Coast.
The match will be Johnson's first in Warriors colours since September, 2018, with the 31-year-old returning after several seasons with the Cronulla Sharks.
Nikorima won the race to partner Johnson, with new recruit Ash Taylor named on the extended bench.
Chanel Harris-Tavita had been given the nod at fullback, filling the void left by suspended young star Reece Walsh.
Addin Fonua-Blake would captain the side, with appointed skipper Tohu Harris not set to return from a knee injury for another couple of months.
Head coach Nathan Brown had shown faith in 20-year-old Rocco Berry and 19-year-old Viliami Villa, naming them to start alongside the wing pairing of Dallin Watene-Zelezniak and Marcelo Montoya.
The only player set to make his club debut was new forward signing Aaron Pene, who had been picked on the bench.
In taking their first-round match to Sunshine Coast Stadium, the Warriors will now be able to count 12 venues where they have played home games, six of those added during the club's Covid-enforced stay in Australia since 2020.
They take a healthy recent record against the Dragons into this contest.
It's the 33rd clash between the clubs overall with St George Illawarra winning 22 of the previous 32 but the Warriors won five on end before being pipped 19-18 by the Dragons at Central Coast Stadium last July.
Warriors: Chanel Harris-Tavita, Dallin Watene-Zelezniak, Viliame Vailea, Rocco Berry, Marcelo Montoya, Kodi Nikorima, Shaun Johnson; Addin Fonua-Blake (c), Wayde Egan, Bunty Afoa, Euan Aitken, Eliesa Katoa, Josh Curran. Interchange (from): Jazz Tevaga, Ben Murdoch-Masila, Aaron Pene, Bayley Sironen; Jack Murchie, Ash Taylor, Adam Pompey, Pride Petterson-Robati, Taniela Otukolo, Jesse Arthars, Edward Kosi.
Photo: Photosport Caption: Shaun Johnson is enjoying being back in the Warriors environment.