Catalans Dragons captain Remi Casty will be out for four weeks after fracturing a rib cartilage in Monday's Super League win over Castleford.
Prop Casty, 31, has played five games in 2016, after having last season cut short by a knee injury.
Les Dracs have Julian Bousquet, Willie Mason, Louis Anderson and Antoni Maria as alternative front-row options.
"It's obviously bad news for him, but also for the team," head coach Laurent Frayssinous said.
"Since his return, Remi was improving week in week out and produced some great performances in the last games.
"But I know him and I'm sure he will come back stronger."