Hull KR captain Shaun Kenny-Dowall has been ruled out for the rest of the season with a knee injury.
Kenny-Dowall, 34, went down awkwardly in a tackle in the defeat to Leeds on Friday and has damaged his medial collateral ligament (MCL).
The club has confirmed that the former New Zealand international is out for the rest of the campaign.
Also ruled out for the remainder of the season is prop Greg Richards.
Richards tore his hamstring shortly into his opening stint off the bench and will see a specialist.
Coach Danny McGuire feared the worst following the defeat to Leeds and has now lost two more players for the run-in.
McGuire said: “I’m not looking for sympathy but I’ve no idea how we’ll look to put a team together next week or the two games the weekend after. We’re not in a good place. Someone might have to help us out there.
“We’re in a good place in terms of togetherness and a team, but injury wise I’ve never seen anything like it. It’s crazy.”
Rovers are already without Will Dagger (achilles) for the season, while Jordan Abdull (quad), Brad Takairangi (hamstring), Dean Hadley (shoulder) and Luis Johnson (pec) are long-term absentees.
There is better news over young half-back Rowan Milnes, who is in contention for the game against St Helens this week.
He suffered a rib cartilage injury in training that ruled him out of the Leeds game.
Mikey Lewis also missed the clash with the Rhinos, but is pushing for a return before the end of August from an ankle strain.
Lachlan Coote could return to face his former club, subject to passing return to play protocols following his second concussion of the year.
Ryan Hall and Kane Linnett returned to the Hull KR line-up against Leeds, as did Phoenix Laulu Togaga’e.
Youngsters Connor Moore and Zach Fishwick are back in full training.
Shaun Kenny-Dowall has started in 22 of Hull KR’s 26 games in 2022, bettered only by George King (23).