There have been suggestions that at least one high profile player was set for the chop, but it's more likely Gaffney will make just three alterations, and even one of them may be positional.
Mike Mullins, who came in as a second-half replacement in Castres, may be handed the number 13 jersey with Shaun Payne switching to the wing for Mossy Lawler and in the continued absence of the injured John Kelly.
Gaffney has a wealth of talent to choose from in the back-row where one of five international players won't even get a seat on the bench.
It may well be that the fit-again Denis Leamy returns at number seven to the exclusion of David Wallace.
Alan Quinlan, another who got a second half call-up in Castres, will push Jim Williams hard at number six.
Castres were again playing their cards close to their chests yesterday but it shouldn't be overlooked that they were extremely unfortunate in the area of injuries last week. They were forced to start without former French out-half Yannick Delaigue and Argentinian hooker Mario Ledesma because of injury and both were still being monitored yesterday.
During the game itself, winger Brad Fleming and centre Mark Denney had to be replaced and things eventually got so bad that Jacques Deen, normally a flanker, came into the back-line when Delaigue's substitute, Xavier Sadourny, also had to depart.
However, the fact that they were able to call on internationals of the calibre of Remi Vigneaux and Richard Dourthe for Ledesma and Denney, the highly-rated Benjamin Lhande for Fleming and Pumas prop Mauricio Reggiardo and French flanker Romain Froment as tactical options in place of Justin Fitzpatrick and Federico Capo Ortega, is its own indication of Castres' strength in depth.