The two clubs, now battling to get out of National League One, last met in a major final at Wembley 19 years ago, when Cas carried off the Challenge Cup with a 15-14 victory.
There will not be quite the same sense of occasion at Bloomfield Road, although the Tigers will take 6,000 fans to the seaside and Rovers almost as many.
Cas need to show that they have got over a shock defeat - their first in the league this season - at Rochdale last week. They could also be badly depleted in the forwards, where Frank and Adam Watene, Aaron Smith and Tom Haughey all face fitness tests.
Rovers' biggest doubt concerns the former Castleford forward Michael Smith, who will also have a late test. They already know they will be without Paul Parker and Phil Hasty, although they have been in excellent form since they sacked their coach, Harvey Howard.
James Webster has done an effective job as caretaker, but he has handed over this week to Justin Morgan, who is still dealing with his responsibilities at Toulouse before relocating to Humberside full-time.
In the Super League today, Hull have the influential Richard Swain back in their side for the first time in four months for the visit of Huddersfield, but are without both Nathan Blacklock and Shaun Briscoe thanks to knee injuries.
Most of the tension tomorrow will be at the Halton Stadium, where Widnes will be looking at a five-point gap and almost certain relegation if they lose to Wakefield.
Widnes were desperately poor in defeat at Salford last weekend, when the Wildcats improved their survival prospects by beating Bradford. The Vikings could include Aaron Moule and Adam Hughes in the centre.
Warrington have Lee Briers back in their squad after a leg injury for a match against the London Broncos which has implications for the pecking order in the top six.
Bradford are no longer looking assured of a place in the play-offs following a run of three matches without a win. If they fail to beat Leigh, the sequence will become their worst in Super League, although they have the Kiwi centre Shontayne Hape back after knee surgery and possibly the powerful Tongan wing Lesley Vainikolo as well.
Leigh, already as good as relegated, are without their best player this season, John Wilshere, who is suffering from a stomach bug. They also face a battle to keep him for the rest of the season, with several of their Super League rivals keen to add him to their squads for the run-in.
"John has been our star player this season and it's going to be hard for him to turn down offers, but we want to keep hold of our best players," said the manager, Mike Callaghan. "We're not into asset-stripping, we're into empire-building."Reuse content