Hull Kingston Rovers forwards Kevin Larroyer and Jordan Cox have been ruled out for around six weeks each through injury.
The pair both suffered fractured ankles on Sunday during their side's 54-12 defeat to Castleford Tigers in the Super League.
"It's very disappointing to lose both Kevin and Jordan for that amount of time," Hull KR coach Craig Sandercock is quoted as saying by Sky Sports News.
"Kevin has been one of our best players this season and Jordan had just come back into the team, so for them both to suffer the same injury within a few minutes of each other is a blow for us.
"They are both important members of our pack but they will be in very safe hands with our medical team and hopefully we'll get them back on the field as soon as possible."
Hull KR continue their Super League campaign on Friday at home to Warrington Wolves.