Winger Liam Bibo, who was due to make his debut, has been forced to cry off with a calf injury, while centre Mel Deane (arm) and prop Robbie Morris (back) have also been ruled out.
Replacement flanker Ray Ofisa has also been ruled out with a shoulder injury.
The enforced reshuffle sees Darren Yapp come in on the right wing, Aidan Wynne start at inside centre, with Ronan Loughney starting at tighthead prop.
Prop Brian McGovern, second row Andrew Browne and flanker Colm Rigney are added to the replacements.
Connacht
15: Gavin Duffy
14: Darren Yapp
13: Danny Riordan
12: Aidan Wynne
11: Ofisa Treviranus
10: Andy Dunne
9: Conor O¹Loughlin
1: Brett Wilkinson
2: Adrain Flavin
3: Ronan Loughney
4: Michael Swift
5: David Gannon
6: Michael McCarthy
7: Johnny O¹Connor
8: John Muldoon (captain).
Replacements:
16: John Fogarty
17: Brian McGovern
18: Andrew Browne
19: Andrew Farley
20: Colm Rigney
21: Conor McPhillips
22: Peter Durcan