Two Super League sides will get some indication today of how they will cope in the absence of pivotal players. For Hull KR, the portents are not good. They lined up without Michael Dobson for the first time in 79 matches last week and squandered an early 12-point lead to lose 32-18 to the Catalans Dragons, last season's wooden-spoon recipients.
The Australian scrum-half has had an operation on his ankle and could be out for three months. Dobson has been such a fixture in the team and such a fulcrum in their play that losing him is a major blow to Rovers' coach, Justin Morgan.
For today's trip to unbeaten Castleford he is likely to persist with the pairing of Blake Green and Scott Murrell. But Dobson's contribution – and especially his top-of-the-range kicking game – is bound to be missed.
Cas had last weekend off, thanks to Wigan's participation in the World Club Challenge. On the admittedly scant evidence of two matches, they seem to have hit upon a well-balanced half-back combination in Rangi Chase and Danny Orr – the right blend of dash and direction. They also have Ryan Hudson back in contention and Nick Fozzard bidding for a debut.
Bradford had their first win of the season last week at Crusaders but it came at a price. Apart from Chev Walker's torn pectoral, which could keep him out for six weeks, the hooker Heath L'Estrange came off at Wrexham with what was thought to be a broken ankle. Scans have not revealed a fracture but he has sustained ligament damage.
At least Bradford have a tried-and-tested replacement in Matt Diskin, the former Test hooker signed from Leeds. He will start against Wakefield today, as should Marc Herbert, the new scrum-half in line for his debut.
Wakefield's win at the Catalans two weeks ago now looks suspiciously like a surge of adrenalin after their rescue from the hands of the administrators. Last week's heavy defeat by Salford could be more typical of what lies ahead, although Trinity's saving grace over the last few seasons has been their ability to follow a hopeless performance with a defiant one.
John Kear is capable of getting another of those out of them. But the theft of their scoreboard last week looks symbolic of the essential pointlessness of their situation, where only the complete collapse of another club can save them from being ejected from Super League. Craig Harvey and Josh Griffin could make their debuts, but Paul King and Ben Jeffries are out.
The rest of the third-round ties in the Challenge Cup are played today, with notable all-professional match-ups between Oldham and Hunslet, Rochdale and Workington, and South Wales Scorpions and Dewsbury.
The best chance of a giant-killing could be at the home of the former winners Sheffield Eagles, who play the best student team in the country, Leeds Met.