Nathan Catt starts a Premiership game for the first time this season as he lines up at prop for Bath against West Country neighbours Gloucester.
Wing Matt Banahan returns in the only other change to the side which beat Scarlets in the European Champions Cup.
Ed Slater is back in the second row for Gloucester following a finger injury.
Jeremy Thrush, Andy Symons and Ollie Thorley are all named on the bench after their recent injury problems, while Billy Burns moves to full-back.
Bath: Watson; Rokoduguni, Joseph, Clark, Banahan; Priestland, Fotuali'i; Catt, Dunn, Perenise, Charteris, Ewels (capt), Mercer, Underhill, Faletau.
Replacements: Walker, Obano, Andrews, Stooke, Garvey, Allinson, Lewis, Brew.
Gloucester: Burns; Purdy, Trinder, Twelvetrees, Halaifonua; Williams, Heinz (capt); Hohneck, Hibbard, Afoa, Savage, Slater, Ackermann, Ludlow, Morgan.
Replacements: Matu'u, Rapava Ruskin, Denman, Thrush, Rowan, Vellacott, Symons, Thorley.