Gerringong forward Hamish Stewart will miss just his second NRL match this year since he was handed his debut back in the opening round when the Dragons travel to Canberra on Saturday.

Stewart suffered a category-one concussion when he came off second best while trying to make a tackle in last Saturday's 34-20 win over Parramatta at WIN Stadium.

His absence is one of several changes St George Illawarra coach Shane Flanagan has been forced to make for the trip to face the in-form Raiders at GIO Stadium in Round 18.

The Green Machine are at the top of the NRL ladder with a 13-3 record after they knocked off the Knights 22-18 in Newcastle last Friday night.

After beating the Eels despite a heavy injury toll, the Dragons have remained in the race for the playoffs with a 6-8 record to sit in 11th place.

Young forward Toby Couchman (shoulder), wingers Nathan Lawson (shoulder) and Christian Tuipulotu (hamstring), second-rower Luciano Leilua (thigh) and Valentine Homes (State of Origin duty) are out from the team named last week.

Tyrell Sloan and Sione Finau have been recalled to be the new wing duo with Corey Allan shifting in to centre.

Veteran forward Raymond Faitala-Mariner has been elevated to start in the second row while Hame Sele, Loko Pasifiki Tonga and Michael Molo - in his first NRL appearance of 2025 - are the new names on the bench.

Flanagan has relegated young forward Viliami Fifita drops to the reserves.