St Helens welcomed back skipper Paul Sculthorpe on Friday but suffered another serious injury blow with the loss of prop Nick Fozzard.
Paul Sculthorpe returned after nine months out injured
Sculthorpe returned mid-way through the first half in Saints' 22-16 win over Bradford after a nine-month spell on the sidelines with an Achilles injury.
However, Fozzard looks set to join Saints' growing injury list with suspected ligament damage.
"Fozzard looks to have a serious knee injury," said coach Daniel Anderson.
"We hope he's wrong but the doctor fears the worst."
Former Great Britain captain Sculthorpe made a steady comeback as Saints held off a spirited fightback to claim their first win at Odsal for three years.
Already without Jason Cayless, Maurie Fas'asavalu, Jon Wilkin and Chris Flannery, Saints also lost teenage front-rower Gareth Frodsham, who was left dazed by a tackle from Bradford's Sam Burgess just four minutes after coming on as an interchange.
"Gareth was rattled and didn't come back for the second half," said Anderson.