Raiders star in doubt for Dragons clash, forward enters concussion protocols

Canberra Raider star Joe Tapine is no certainty to line up against the Dragons this weekend after suffering a rib injury in Saturday night's loss to Penrith.

Tapine was unable to finish the 6-26 defeat at GIO Stadium due to the ailment, placing the 28-year-old in doubt for his side's Round 22 clash with St George Illawarra.

The Raiders confirmed on Monday that Tapine will require further assessment on the rib injury, with the in-form forward needing to prove his fitness in the next 24 hours.

Semi Valemei joins Tapine in suffering a rib injury and also faces further assessment on Tuesday before the club can confirm his selection status.

Meanwhile, Canberra will likely be without Ryan Sutton due to a head knock sustained in the Round 21 loss to the Panthers, with the Raiders prop entering concussion protocols and facing further tests on his ability to feature this weekend.

The Raiders have announced that duo Corey Horsburgh (illness) and Trey Mooney (ankle) will be in line for a comeback after returning through the NSW Cup on Saturday.

The Raiders are already without Nic Cotric (suspension), Harry Rushton (jaw), Jarrod Croker (shoulder), Josh Hodgson (knee) and Harley Smith-Shields (knee) for at least this week.

Canberra will confirm their squad for Round 22 at 4:00pm (AEDT) on Tuesday, before hosting the Dragons at GIO Stadium on Sunday afternoon at 2:00pm.