St Helens can come close to guaranteeing themselves the League Leaders' Trophy and the advantages of going into the Super League play-offs in first place if they win at Headingley today.
Victory over Leeds will give Saints a six-point lead with six matches left. It would not be an impossible gap to close, but it would be unlikely in view of Saints' consistency this season.
Their coach, Daniel Anderson, has complained about the disruption caused by Great Britain training this week, but he is likely to have Sean Long back. Francis Meli is still out.
Leeds have Kevin Sinfield back after he missed last week's shock 31-30 loss to Castleford with a dead leg. Gareth Ellis also returns after being rested.
The newly-installed Harlequins coach, Brian McDermott, is likely to give a debut to one of his two new signings today, with Paul Noone in the squad to face Hull, the third-placed side from whom Anderson fears a late run.
Hull will be without Gareth Raynor and Garreth Carvell and the previously ever-present Paul Cooke, who has had an operation to remove a kidney stone. His absence will give the highly-rated teenage half-back Tommy Lee a chance to start.
Richard Horne, having equalled a 91-year-old Hull record by scoring in an 11th consecutive game last weekend, can set a new mark if he scores today.
Against Salford, the Catalans Dragons are set to give a first appearance to the prop, Matthieu Griffi, they signed this week from their sister club UTC.
Salford will be coached by James Lowes - the man Wakefield approached this week about taking on the task of steering them away from relegation - because of the absence of Karl Harrison with a ruptured Achilles tendon.
David Gower, the British-qualified back-row forward signed from the Australian club Wests Tigers, is in the Reds squad for the first time.
Wigan have farmed out yet another player as they juggle with their salary cap, the centre Sean Gleeson joining Widnes, initially on a month's loan.
Wigan are at Warrington tomorrow and can further improve their survival chances with a win, while the winners of the match between Huddersfield and Castleford will surely be safe.
Gleeson could make a debut against Hull Kingston Rovers, unbeaten in National League One but still stinging from their defeat by Leigh in last Sunday's Northern Rail Cup final.Reuse content