Chris Henry has been ruled out of the Heineken Cup semi-final with Edinburgh at Lansdowne Road on Saturday.
Henry has failed to recover from an ankle sprain picked up in the PRO12 match against Leinster last weekend.
Paddy Wallace, Pedrie Wannenburg and Paul Marshall have all been passed fit, with scrum-half Marshall settling for a place on the bench.
Forwards Stephen Ferris, Dan Tuohy and Rory Best all return to the starting team after being rested last weekend.
Best replaces Nigel Brady, while Lewis Stevenson makes way for Tuohy, and Ferris is a direct replacement for Henry. Declan Fitzpatrick will start again at tighthead prop.
Coach Brian McLaughlin has named an unchanged backline, meaning Ireland U20 captain Paddy Jackson is preferred over Ian Humphreys at out half.
Coach Brian McLaughlin is confident that the inexperienced Jackson will take the pressure in his stride.
"Paddy has come in over the last few weeks and done exceptionally well. His performances have warranted selection. It's a very tough call on Ian (Humphreys) who has been exceptional for us over the past couple of seasons, but we felt Paddy deserved a shot."
Edinburgh head coach Michael Bradley has named the same team which secured the 19-14 win over four-time European champions Toulouse in the last round on April 7.
Ulster: S Terblanche; A Trimble, D Cave, P Wallace, C Gilroy; P Jackson, R Pienaar; T Court, R Best, D Fitzpatrick, J Muller (capt), D Tuohy, S Ferris, W Faloon, P Wannenburg Replacements: N Brady, P McAllister, A Macklin, L Stevenson, R Diack, P Marshall, I Humphreys, A D'Arcy
Edinburgh: T Brown; L Jones, N De Luca, M Scott, T Visser; G Laidlaw (capt), M Blair; A Jacobsen, R Ford, G Cross, G Gilchrist, S Cox, D Denton, R Rennie, N Talei Replacements: A Kelly, K Traynor, J Gilding, S Turnbull, R Grant, C Leck, P Godman, J Thompson