With games running out, Rainey Old Boys are eager to secure play-off rugby and could take a massive step towards nailing down third place by beating Greystones at Hatrick Park.
It will be Rainey's penultimate home game in the regulation season, though their visitors are in second and 15 points in front and, as such, are looking assured of keeping their place in the table for a home play-off semi-final.
As things stand, that would mean Rainey going to Greystones for a play-off but the Magherafelt club are rather more concerned with keeping Sligo at bay, who are a just point behind them in fourth. However, John Andrews' squad could secure a top four finish should they get a good result over tomorrow's visitors.
Rainey welcome back former Ulster lock Tim Barker after a lengthy spell out with injury, while Paddy McGowan and Damian McMurray also return to action.
Charlie Clarke is with Ulster 'A' so Andrew Harbinson comes in to the back-row as Rainey chase back-to-back wins.
Further down the table, a relegation dogfight awaits at Deramore where ninth placed Belfast Harlequins play out an Ulster derby with Dungannon, who are now in seventh but only six ahead of Nicky Wells' squad.
Gannon have won three of their last four games and will be looking to bring this edge to struggling Quins who badly need a result.
In 2A, Queen's University's rich vein of form has seen them win their last four games and take maximum return from each one to rack up 20 points.
With Navan four in front of Queen's, UL Bohemians four behind and Old Crescent just outside the play-offs but six back from the students, Derek Suffern's side need to keep the winning run going at bottom side Galwegians.
In 2C, struggling Bangor host second-placed Midleton and need a win after losing eight on the spin. Both Omagh, in fifth, and sixth-placed City of Derry can do Bangor a favour by winning their respective games against Thomond and Seapoint.
2A: Galwegians v QUB
2B: Belfast Harlequins v Dungannon, Rainey v Greystones
2C: Bangor v Midleton, Omagh v Thomond, Seapoint v Derry