Shannon, at home to Ballymena at the weekend in their second All-Ireland League match of the season, have been told by the IRFU to play the match on Saturday.
The Limerick side, which may have several players involved in Munster's second European Cup match against Harlequins at The Stoop on Saturday, sought to have the game played on Friday when all players involved with Munster and Ulster would have been unavailable. Sunday was the alternative date when the bench players from both provinces would have been available.
Ballymena, who have players involved in the European Cup match against Wasps on Friday, do not play matches on Sunday and did not wish to play on Friday. As the teams could not agree, the IRFU ruled that the match should stay on its original date. As such, Ballymena will not select until Saturday morning when they know what players they have from the Ulster squad, while Shannon will have none of their Munster contingent.
To complicate Shannon's preparation, full back John Lacey will be out of action after leaving the pitch against UCD with a shoulder injury. Lacey will be sidelined for a month.
Terenure hope to have an injury-free squad against Galwegians. Although Steve Barretto went off injured against St Mary's on Saturday, he is expected to be available. Doubt hangs over the Galway side's full back Robby Lee and centre Noel O'Meara. Lee has been suffering with a hamstring injury while O'Meara has a shoulder injury.
St Mary's College face Buccaneers without Barry Lane, who is out because of a cheek problem but may have to change the side on Saturday depending on what players Leinster use on Friday evening.
Buccanneers await the fitness of right wing Mike Devine, who took a heavy knock against Galwegians last weekend with Ted Robinson again fit in the event of Devine being ruled out.
Clontarf hope wing forward Andy Cullen will be available for selection for their home game against DLSP. Having recovered from an AC joint injury, Cullen joins an otherwise fit squad. UCD, also declaring no serious injuries, keep with the side that earned them their first AIL win ever over Shannon.
Blackrock hope to have captain Michael Jackson fit for next week's midweek game against Lansdowne. Jackson is recovering from a rotator cuff injury. Back row Rory Rogers is also in harness again having taken time out of the game for personal reasons.
Lansdowne hope to have former captain Dave O'Mahony back contesting for the scrum half position and also the injured centre Dave P O'Mahony .
ST MARY'S COLLEGE: P McKenna; J Norton, K Lewis, G Gannon, J McWeeney; A Conboy, C McPhillips; P Coyle*, G Hickie*, D Clarke, E Keane, J Ryan, M Brown, S Jennings, K Jennings. (* if available)