Widnes Vikings captain Kevin Brown has been ruled out of action for up to six weeks due to an ankle injury.
The 30-year-old stand-off, who has scored 16 tries in 15 games so far this season, Brown recently signed a new deal with the club until 2018.
"It's pretty tough to take, really," Widnes head coach Denis Betts told BBC Sport. "At this stage of the year it's a tough one not just for us, but for Kevin himself, as his form this year has been fantastic."
Widnes continue their Super League campaign on Sunday when they travel to Castleford Tigers.