St Helens scrum-half Luke Walsh has been sidelined for up to four weeks after undergoing ankle surgery.
The Australian sustained the injury during his side's 33-26 defeat to Catalans Dragons last weekend.
Walsh, 28, missed the Saints' first 10 matches of the season due to a broken leg and damaged ankle.
"It is a blow as we have a big block of five games coming up but we will cope and Walsh will return," coach Kieron Cunningham is quoted as saying by Sky Sports News.
St Helens are back in Super League action on Friday when they travel to Hull FC.