Canterbury Bulldogs forward Dylan Napa is expected to miss 5-6 weeks after suffering an ankle injury during his side's loss to the Storm on Sunday.
Napa sustained a grade two syndesmosis injury to his right ankle, which is the same injury teammate Kieran Foran suffered last week.
The Dogs are 1-3 on the season so far, and begin life with Napa this Sunday against the Dragons.
St George will be without Korbin Sims for the next 6-8 weeks, after he broke his forearm against the Knights.
"Korbin Sims suffered a broken forearm in the Dragons' win over the Newcastle Knights on Sunday afternoon," St George Illawarra Head of Athletic Performance Nathan Pickworth told the club's website.
"Korbin will undergo surgery on Monday afternoon to stabilise the fracture; his return to play will be approximately six to eight weeks."