Mike Cooper spent the early part of last season on loan with Castleford
Warrington prop Mike Cooper has been ruled out for up to eight weeks with a shoulder injury as coach Tony Smith counts the cost of Magic Weekend.
Cooper, 22, one of a number of Wolves players hurt in the season-opening Super League defeat to Huddersfield, has damaged his AC joint.
Chris Bridge has been ruled out for up to four weeks with a torn hamstring.
But fears that Aussie centre Matt King, might miss the rest of the season have been calmed after a more positive scan.
The former Australia international was thought to have ruptured his anterior cruciate ligament, which would have effectively ended his season.
But the injury may be confined to his medial ligament and damage to the joint capsule in his right knee - which would ordinarily mean a lay-off of only eight to 12 weeks.
After scans showed that King's knee injury may not be as serious as first feared, Warrington head physio John Hartley said: "We are still awaiting the all-clear from a specialist.
"But the early signs indicate that the damage is hopefully not as severe as first thought.
"He is due to see a specialist this week to find out how long the injury is likely to keep him on the sidelines for."
Everyone is feeling sorry for us and that's nice. But we'll be okay. We're not in too bad shape
Warrington coach Tony Smith
Wolves played the last few minutes at the Millennium Stadium with only 12 men on Saturday, having lost five players and used up all their interchange players in the opening day Magic Weekend 28-18 defeat against Huddersfield.
Lee Briers also had a precautionary X-ray on his neck after going off with concussion.
And Smith is hopeful that Simon Grix could recover from a dead leg to face Hull KR on Sunday.
But hooker Jon Clarke, who missed the trip to Cardiff with a calf problem, is again doubtful.
Despite his much-fancied side's slip-up against a Huddersfield team who ended the Challenge Cup winners' 2010 Super League hopes in the play-offs in September, Smith refused to use the queue for the Cardiff treatment table as an excuse for.
"Everyone is feeling sorry for us and that's nice," said Smith. "But we'll be okay. We're not in too bad shape."