Gloucester boss Dean Ryan:
"We have lost some of our key decision makers including Alex Brown (injured), but we need our guys to step up and they haven't done that.
"We've taken his role in this squad for granted for too long and because of that we looked startled and surprised.
"We can't base a side around one man. If that's a lesson we have to learn publicly then so be it."
London Irish: Flutey; Armitage, Penney, Catt, Bishop; Everitt, Willis; Hatley, Coetzee, Rautembach; Casey, Kennedy; Roche, Danaher, Murphy.
Replacements: Mordt for Catt (75), Hodgson for Willis (69), Russell for Coetzee (69), Skuse for Rautembach (61), Strudwick for Casey (77), Gustard for Murphy (61).
Not Used: Horak.
Gloucester: Morgan; Garvey, Simpson-Daniel, Fanolua, Thirlby; Mercier, Thomas; Collazo, Parkes, Powell; Eustace, Davids; Buxton, Boer, Forrester.
Replacements: B Davies for Garvey (73), Allen for Fanolua (59), Richards for Thomas (40), Wood for Collazo (16), Balding for Boer (10).
Not Used: Elloway, Pendlebury.
Sin bin: Eustace (49), Buxton (76).
Att: 9,027
Referee: Ashley Rowden (RFU)