Wallace was always a doubt while Hayes injured his shoulder in his side's win over Llanelli but the biggest blow was the withdrawal of Henderson. The Lions centre who made such an impression in the win over Llanelli, twisted a knee in training yesterday and will be out of action for up to four weeks. The Munster side shows four changes from last weekend, Dominic Crotty returns from injury and fills the number 15 berth, Peter Stringer also returns from injury to take up sation at the base of the scrum, Marcus Horan replaces Hayes while Paul O'Connell will partner captain Mick Galwey in the second row.
Ulster coach Alan Solomons has no such problems and was able to name an unchanged side this afternoon.
Leinster coach Matt Williams also named an unchanged side with Nathan Spooner and Eric Miller fully recovered from injuries picked up against Newport.
Munster. Dominic Crotty; John Kelly, Mike Mullins, Jason Holland, Anthony Horgan; Ronan O'Gara, Peter Stringer; Marcus Horan, Frank Sheahan, Peter Clohessy; Mick Galwey capt, Paul O'Connell; Jim Williams, Alan Quinlan, Anthony Foley.
Replacements. Martin Cahill, James Blaney, Mick O'Driscoll, Colm McMahon, Mike Prendergast, John O'Neill, Jeremy Staunton.
LEINSTER (v Glasgow): G Dempsey; D Hickie, B O'Driscoll, S Horgan, G D'Arcy; N Spooner, B O'Meara; R Corrigan (capt), S Byrne, P Wallace; L Cullen, M O'Kelly; E Miller, V Costello, K Gleeson.
Replacements: P Coyle, G Hickie, B Casey, T Brennan, B Willis, P McKenna / S Keogh, A Magro.
ULSTER.: P Wallace; J Topping, A Larkin, J Bell, T Howe; D Humphreys, N Doak; J Fitzpatrick, P Shields, S Best; G Longwell, M Blair; T McWhirter, A Ward (capt), R Nelson. Reps: 16 M Crick, 17 C Boyd, 18 J Davidson, 19 N McMillen, 20 J Campbell, 21 R Constable, 22 S Coulter.