Ben Botica has been handed the fly-half shirt for Harlequins' trip to face Connacht.
The young New Zealander fills in for the injured Nick Evans in his first start for the club.
Winger Ugo Monye is also ruled out with an ankle injury and is replaced by Sam Smith.
Connaght coach Eric Elwood makes just one change to his lineup, with Adrian Flavin starting in the front row.
Connacht: Henshaw, O'Halloran, Griffin, McSharry, Vainikolo, Parks, Marmion, Buckley, Flavin, White, Swift, McCarthy, Muldoon, Faloon, Naoupu
Harlequins: Brown, Williams, Hopper, Turner-Hall, Smith, Botica, Care, Marler, Buchanan, Johnston, Kohn, Robson, Fa'asavalu, Robshaw, Easter
