Bath head coach Mike Ford has made seven changes to the starting line-up for the club's first home match of 2016, following three consecutive games on the road.
Nick Auterac, Ross Batty and Henry Thomas make their seventh start of the season together in the front row. In contrast, locks Charlie Ewels and Dominic Day (this week named in Wales's Six Nations squad) combine for the first time.
A new-look back row comprises blindside David Denton (included in Scotland's Six Nations squad this week), openside Guy Mercer and last weekend's try-scorer, number eight Leroy Houston.
Chris Cook makes his 60th club appearance at scrum-half, with half-back partner George Ford named captain for the match.
Horacio Agulla comes in on the left wing, joining fellow wing Semesa Rokoduguni and full-back Anthony Watson in the back three.
Meanwhile, Toulon make four changes to the XV who edged out Wasps last weekend at the Stade Félix Mayol.
James O'Connor takes over from Drew Mitchell at full-back, with Maxime Mermoz in at outside centre for Mathieu Bastareaud.
The two remaining changes see Sébastian Tillous-Borde take over from Eric Escande at scrum-half, while Samu Manoa returns to partner Jocelino Suta in the second row.
Form: Bath have won three of their last four home matches in the Champions Cup. However Toulon have won five of their last seven away from home in the competition; four of those wins came by 10 points or fewer. Five of the last six matches in which Bath have hosted a French side in the Champions Cup have been decided by a margin of three points or fewer, including one draw. Toulon are currently undefeated in the penultimate pool stage fixture of the Champions Cup (W4) although all those games were home fixtures for the French side. Toulon have conceded just 39 penalties this season so far, no other side has conceded fewer than 45. However, Toulon have conceded the most turnovers in the Champions Cup this season, averaging 20 per game
Bath: 15 Anthony Watson, 14 Semesa Rokoduguni, 13 Jonathan Joseph, 12 Kyle Eastmond, 11 Horacio Agulla, 10 George Ford (c), 9 Chris Cook, 8 Leroy Houston, 7 Guy Mercer, 6 David Denton, 5 Dominic Day, 4 Charlie Ewels, 3 Henry Thomas, 2 Ross Batty, 1 Nick Auterac
Replacements: 16 Tom Dunn, 17 Nathan Catt, 18 David Wilson, 19 Tom Ellis, 20 Matt Garvey, 21 Alafoti Faosiliva, 22 Rhys Priestland, 23 Ollie Devoto
Toulon: 15 James O'Connor, 14 Josua Tuisova, 13 Maxime Mermoz, 12 Ma'a Nonu, 11 Bryan Habana, 10 Quade Cooper, 9 Sébastien Tillous-Borde, 8 Duane Vermeulen, 7 Steffon Armitage, 6 Juan Smith, 5 Samu Manoa, 4 Jocelino Suta, 3 Levan Chilachava, 2 Guilhem Guirado, 1 Florian Fresia
Replacements: 16 Jean-Charles Orioli, 17 Xavier Chiocci, 18 Manasa Saulo, 19 Mamuka Gorgodze, 20 Romain Taofifenua, 21 Mathieu Bastareaud, 22 Eric Escande, 23 Thibault Lassale
Date: Saturday, January 23
Venue: The Recreation Ground
Kick-off: 15:15 GMT
Referee: Nigel Owens (Wales)
Assistant Referees: Rhys Thomas (Wales), Gwyn Morris (Wales)
TMO: Derek Bevan (Wales)