Connacht coach Michael Bradley believes six points from the next two Rounds can secure a quarter-final spot for the Irish province.
It is a much altered side from that which played against the Scarlets on Friday with twelve changes to the starting fifteen.
Bradley is linking Saturday's tie with the final pool game the following Friday at home to French side Dax - Connacht need to win at least one of those games to book a quarter-final spot.
"We are taking the two games as a pair and will be using our full squad over the two games. We have made a lot of changes as the same team, more or less, has played the last three matches against Munster, Leinster and the Scarlets in thirteen days and could not be expected to play five games in a row.
"We need a win and probably a bonus point from these two games and that should be enough for us to qualify," said Bradley.
Connacht look to be aiming for one of the runners-up spots as London Irish, currently six points ahead, would need to lose to both Connacht and Italian side Rovigo to be overtaken.
Former London Irish hooker Adrian Flavin will captain the Connacht side.
Connacht team: (v London Irish)
D Riordan; F Carr, J Hearty, M Deane, T Nathan; A Dunne, K Campbell; J Lyne, A Flavin (C), R Loughney; M Swift, A Farley; A Browne, D Gannon, C Rigney.
Replacements: J Merrigan, B McGovern, M McCarthy, J Muldoon, C O'Loughlin, I Keatley, M Roberts.