The removal of the South African muscle of tight-head Wiehahn Herbst (foot) and second row Franco van der Merwe (ankle) from Ulster's front five could haunt them in this PRO12 semi-final at Scotstoun tonight.
Emerging Ireland anchorman Ricky Lutton will have to shoulder the responsibility to hold up Ryan Grant at the scrum, while Lewis Stevenson is a long way off the standards set by van der Merwe.
Ulster coach Neil Doak will want a rock solid set-piece to undermine Glasgow's home advantage.
The importance of Iain Henderson grows with every week and his value as their most destructive ball-carrier is sure to be monitored closely by the Scots. The half-backs Ruan Pienaar and Paddy Jackson are on form and in possession of a three-quarter line that can strike from anywhere as Doak makes 11 changes from last week.
Glasgow coach Gregor Townsend will know better than to take anything deep and meaningful from the 32-10 win last Saturday on the occasion of the final home matches for captain Ali Kellock, Niko Matawalu and Van der Merwe.
Glasgow: S Hogg; T Seymour, R Vernon, P Horne, N Matawalu; F Russell, H Pyrgos; R Grant, F Brown, R de Klerk, J Gray, A Kellock (capt), J Strauss, C Fusaro, A Ashe.
Ulster: L Ludik; T Bowe, J Payne, D Cave, C Gilroy; P Jackson, R Pienaar; C Black, R Best (capt), R Lutton, L Stevenson, D Tuohy, I Henderson, C Henry, R Wilson.
GLASGOW v ULSTER, scotstoun, tonight, 7.45 (live tg4/ss3/bbcni)