O'Halloran signing gives Connacht Christmas cheer as they eye Ulster scalp in Galway
With the Toyota Cheetahs competing at the top of Conference A, the South Africans' ineligibility for Europe means that Connacht are duelling with Cardiff Blues for that final automatic Champions Cup spot and they trail the Welsh region by one point.
Ulster, meanwhile, need to keep tabs on Scarlets and Leinster at the top of Conference B and will enter this game buoyed by their recent Champions Cup performances.
Fresh from signing a two-year contract with the province, Tiernan O'Halloran returns at full-back.
He is joined by Niyi Adeolokun and Matt Healy, who scored four tries in Connacht's win over Brive last weekend. Jack Carty and Kieran Marmion form the half-back pairing after Marmion, another to sign on the dotted line with relatively litle fanfare of late, was rested in the win against Brive.
In the pack, Denis Coulson comes in at loosehead in place of the injured Denis Buckley.
He is joined in the front-row by hooker Shane Delahunt and Finlay Bealham at tighthead.
In the back-row, flanker Jarrad Butler returns from an injury he picked up at home to Munster in October.
Ulster centre Darren Cave, who made his first appearance for the Province against the Border Reivers in April 2007, will become the sixth Ulster player to breach the 200 cap barrier; he starts at inside centre, where he will be paired in midfield with Louis Ludik.
In the back three, Andrew Trimble returns to the starting XV on the left wing, with Craig Gilroy retained on the right and Jacob Stockdale shifting to full-back. Peter Nelson is named to start at out-half, alongside scrum-half John Cooney, who will make his first return to Galway since joining Ulster from Connacht last summer.
Europe has provided a welcome relief for Connacht, who have lost their last two Guinness PRO14 matches, both away from home, at Cardiff Blues and at Zebre, but gained maximum league points from their back-to-back European Challenge Cup encounters against Top-14 opponents Brive over the last two weekends.
Ulster are unbeaten in their last five matches in all tournaments since their 25-10 reversal at home to Leinster and have not lost anywhere on the road since La Rochelle in October.
Connacht have won just one of their last 11 meetings against Ulster, a 30-25 win in Galway in October 2016 and might fancy taking a scalp here.
Connacht - T O'Halloran; N Adeleokun, B Aki, T Farrell, M Healy; J Carty, K Marmion; D Coulson, S Delahunt, F Bealham, U Dillane, Q Roux, E Masterson, J Butler, J Muldoon (capt). Reps: T McCartney, P McCabe, C Carey, J Cannon, N Dawai, J Mitchell, E Griffin, D Leader.
Ulster - J Stockdale; C Gilroy, L Ludik, D Cave, A Trimble; P Nelson, J Cooney; A Warwick, J Andrew, W Herbst; M Dalton, R Diack; I Henderson (capt), S Reidy, N Timoney.
Reps: A McBurney, S van der Merwe, R Kane, M Rea, C Ross, P Marshall, J McPhillips, R Lyttle.
Ref - M Adamson (SRU)
Connacht v Ulster,
Live, TG4 / BBC 2 NI, 7.35pm