In Leinster, Gary Ella must plan for his side's trip to Rodney Parade and a tough encounter with Gwent Dragons without 9 frontline players who are involved with the national squad plus a host of others who are unavailable through injury.
Ella's compatriot, Alan Gaffney has eight of his squad absent through international call-up and up north Alan Solomons will be without David Humphreys and Tyrone Howe while Neil Doak is rested.
Connacht (v Celtic Warriors, Brewery Field. Sat): M Mostyn; T Robinson, D Yapp, M McHugh, C McPhillips; D Hewitt, C Keane; W O'Kelly, J Fogarty, A Clarke; M McCarthy, A Farley; M Swift, P Neville, J O'Sullivan. Replacements: B Jackman, P Bracken, D Browne, T Carter, C O'Loughlin, E Elwood, T Allnutt.
Leinster: (v Gwent Dragons, Rodney Parade): J Norton; J McWeeney, C Warner, D Quinlan, B Burke; B O'Meara, B O'Riordan; J Moran, G Hickie, P Coyle; A Kearney, B Gissing; S Crawford, S Jennings capt, C Potts. Replacements: S Brophy, D Blaney, N Ronan, R Connolly, J Downey, D O'Shea, N O'Brien.
Munster (v The Borders): J Staunton; M Lawler, J Jones-Hughes, R Henderson, A Horgan; J Holland capt, E Reddan, S Kerr, J Blaney, G McIlwham; T Hogan, D Pusey; P Malone, D Wallace, S Keogh.
Ulster (v Llanelli Scarlets, Ravenhill): B Cunningham; J Topping, S Stewart, P Steinmetz, T Howe; A Larkin, K Campbell; R Kempson, P Shields, R Moore; M McCullough, R Frost; A Ward capt, N Best, R Wilson. Replacements: M Sexton, S Best, M Mustchin, W Brosnihan, N Doak, P Wallace, S Young.