St George Illawarra coach Nathan Brown says his side will need to pick up the slack to cover the loss of starting front-rowers Justin Poore and Jason Ryles in Friday's crunch game against Wests Tigers at WIN Stadium.

Poore was yesterday ruled out for up to six weeks with a knee injury and Ryles will miss his second straight match with a thigh strain.

The two props have been the cornerstone of the Dragons' solid form this season and Brown admits it will be tough to replicate their impact and work rate.

"They've both had outstanding years, but it just means collectively everyone has just got to come in and work that little bit harder," Brown said.

"You never like to be down any players, especially two guys that have been in the best form of their careers."

Brown said he was especially disappointed for Poore, whose injury occurred after he was named in a preliminary Australian squad for the Rugby League World Cup.

"It's unfortunate, not only for the club, but for Poorey as well," Brown said. "Just getting named in that Australian squad was a great reward for what's been an outstanding year for him."

Brown said the shoulder injury to fullback Brett Morris could herald the return to first grade of Wendell Sailor, who scored two tries for the Burleigh Bears in the Queensland Cup on Sunday.

He may move winger Jason Nightingale to fullback against the Tigers and Sailor to the wing.