St George Illawarra Dragons veteran hooker Andrew McCullough failed to finish Friday night's clash with the Penrith Panthers after suffering a suspected fractured elbow.

In a game marred by controversy includingnumerous players being withdrawn by the bunker for head injury assessments, McCullough was brought from the field early in the second half with a worrying looking arm injury.

He was then seen on the bench a short time later with his arm in a sling.

The club believe he has suffered a suspected elbow injury, telling broadcaster Fox Sports that he will go for scans in the coming days to confirm the extent of the injury.

It's thought McCullough could miss a month with the injury if confirmed, although it will depend on severity and what structural damage has been done to the joint.

Provided McCullough spends time on the sideline, it could well be Moses Mbye who is named to start at hooker after a strong showing from the bench following the veteran's exit from the game.

Hooker is a position where the Dragons have minimal depth in their squad, with Jayden Sullivan spending time there at the back end of last year.

The Dragons would ultimately fall to Penrith 20 points to 16 after a late second half comeback to set up a grandstand finish.

St George Illawarra will take on the Cronulla Sharks next Thursday evening in the local derby, while the Panthers, who also have question marks regarding star winger Brian To'o, who went off with a knee injury, will face the Newcastle Knights in Bathurst on Saturday afternoon.