Bath include England World Cup trio Sam Underhill, Jonathan Joseph and Ruaridh McConnochie for Saturday's European Champions Cup opener against Ulster.
All three will be making their first Bath appearances since the tournament in Japan.
Iain Henderson returns to Ulster duty after the World Cup with Marcell Coetzee, Jacob Stockdale and Will Addison also starting.
Ulster fly-half Billy Burns will be in opposition to his brother Freddie.
Bath's director of rugby Stuart Hooper names Burns at full-back with Joseph partnering Wales and British and Irish Lions player Jamie Roberts at centre and another Wales international, Rhys Priestland, selected at fly-half.
Priestland will link up at half-back with Will Chudley, who was a try scorer in last weekend's victory over Northampton Saints.
Underhill, man of the match in England's World Cup semi-final win over New Zealand, is named in the back row alongside Mike Williams and Zach Mercer.
Henderson, who will lead Ulster for the first time after returning from Ireland's disappointing World Cup campaign, will partner summer signing Sam Carter in the second row with Coetzee joining another, Jordi Murphy, and Matthew Rea in the back row.
Rob Lyttle retains his place at wing despite Louis Ludik's return to fitness while Rob Herring, who like Murphy was called up to Ireland's World Cup squad as a replacement, joins fellow internationals Jack McGrath and Marty Moore in the Ulster front row.
Bath's win over Northampton left them ninth in the Premiership table with Hooper's team having also defeated Exeter in addition to losing against Wasps and Bristol.
Ulster were edged out by Munster at Thomond Park last weekend but still lie second in Conference A after winning four of their opening six games.
Bath: Burns; Rokoduguni, Joseph, Roberts, McConnochie; Priestland, Chudley; Obano, Dunn, Stuart; McNally, Ewels (capt); Williams, Underhill, Mercer.
Replacements: Walker, Boyce, Judge, Stooke, Bayliss, Cook, Wright, Hamer-Webb
Ulster: Addison; Lyttle, Marshall, McCloskey, Stockdale; Burns, Cooney; McGrath, Herring, Moore; Henderson (capt), Carter; Matthew Rea, Murphy, Coetzee.
Replacements: McBurney, O'Sullivan, O'Toole, O'Connor, Reidy, Shanahan, Curtis, Ludik