St George Illawarra's hopes of making the NRL finals are fading fast after last Friday's 50-point drubbing at the hands of the Dolphins.

They get a chance to put their playoff campaign back on track on Thursday night when they travel to Shark Park to take on traditional rivals Cronulla.

Dragons coach Shane Flanagan has made several changes to the side that was thrashed 56-6 at Suncorp Stadium although he has been forced to make a couple of changes due to injury and State of Origin.

Veteran centre Valentine Holmes is out after being retained by Queensland for next Wednesday's Origin clash in Perth with Corey Allan returning to the side in his place.

Dragons winger Christian Tuipulotu has been sidelined after aggravating his hamstring injury early in the Dolphins defeat with Tyrell Sloan regaining his spot on the flank.

Front-rower Blake Lawie has been dropped and second-rower Raymond Faitala-Mariner will also miss the Sharks showdown after suffering an asthma attack during last week's loss.

Gerringong forward Hamish Stewart has been relegated to the bench after starting at lock against Redcliffe with Jack de Belin getting the No.13 jersey.

Stewart made 36 tackles and only missed two but made just 66 running metres in 52 minutes of game time.

He has played 11 matches in his rookie season and has started in the past five matches.

Hame Sele and Emre Guler have been added to the pack to face Cronulla as St George Illawarra try to rebound after dropping to 11th place on the ladder with a 5-7 record.

Flanagan said in the post-match media conference that the poor showing in Round 14 would not happen again.

"I'll make sure of it. Don't you worry. That's my job," Flanagan said.

"We can make excuses but we are not here to make excuses. It just wasn't up to standard. It is really disappointing.

"It's not acceptable for the Dragons."