Quins winger Ross Chisholm faces up to eight weeks on the sidelines after injuring his knee at Leicester Tigers last week.
Chisolm misses this weekend's visit of Saracens on Sunday after picking up the injury making a try-saving tackle in his side's 22-9 triumph at Welford Road.
Tom Williams, who pulled up in the process of scoring last week, is also missing for the clash with the former Premiership champions with Seb Stegmann taking his place on the wing.
Ollie Lyndsay-Hague comes into the squad on the bench as a replacement for Chisholm, while Maurie Fa'asavalu will also start the match on the sidelines with Tom Guest prefered on the flank.
Harlequins team to face Gloucester:15. Mike Brown, 14. Seb Stegmann, 13. Matt Hopper, 12. Jordan Turner-Hall, 11. Ugo Monye, 10. Nick Evans, 9. Danny Care; , 1. Joe Marler, 2. Joe Gray, 3. James
Johnston, 4. Olly Kohn, 5. George Robson, 6. Tom Guest, 7. Chris Robshaw, 8. Nick Easter
Replacements: 16. Rob Buchanan, 17. Mark Lambert, 18. Will Collier, 19. Charlie Matthews, 20. Maurie Fa’asavalu, 21. Karl Dickson, 22. Rory Clegg, 23. Ollie Lindsay-Hague.