St Helens winger Adam Swift faces at least a month on the sidelines with a shoulder injury.
Swift, 24, was forced off barely five minutes in to the win at Hull KR on Friday.
Coach Justin Holbrook said: “Unfortunately, he’ll be out for a few weeks.
“We lost him after only five minutes and that can happen in the game, and we handled that well and got on with it.
“It’s disappointing for Swifty, he’s been training and playing fantastic so it’s a bit of a shame for him, but we’ll be OK.”
Swift sat out the opening game against Castleford but has since played in all six of Saints’ games, scoring two tries.