Winger Tom Howe will make his first Premiership appearance of the season as Worcester make one change for the visit of London Irish.
Howe replaces Melani Nanai (shoulder) for a Warriors side who conceded five tries in the final 20 minutes to lose 36-3 at Gloucester last Friday night.
London Irish hand a debut to Samoa wing Belgium Tuatagaloa, who signed a deal until the end of the season on Monday.
The Exiles also make five changes in the pack from the side beaten by Bath.
Only second row Adam Coleman and back-rowers Blair Cowan and Albert Tuisue keep their starting places.
Lock Franco van der Merwe, who captains the side, flanker Matt Rogerson and a new-look front row of props Allan Dell and Lovejoy Chawatama and hooker Motu Matu'u all come in.
Form guide
Worcester: Pennell; Humphreys, Beck, Mills, Howe; Weir, Hougaard; Black, Moulds, Schonert, Bresler, Kitchener, Hill, Lewis, Du Preez.
Replacements: Miller, Bower, Palframann, Fatialofa, Van Velze, Heaney, Lance, Shillcock.
London Irish: Veitokani; Tuatagoloa, Rona, Stephenson, Hassell-Collins; Myler, Phipps; Dell, Matu'u, Chawatama, Van der Merwe, Coleman, Rogerson, Cowan, Tuisue.
Replacements: Fainga'a, Elrington, Hoskins, Nott, Mafi, Meehan, Campbell, Stokes.