Harlequins have benched Danny Care, Joe Marler and George Lowe for Friday's Amlin Challenge Cup quarter-final with Toulon at Stade Félix Mayol.
Ugo Monye returns to the line-up having sat out of the Wembley victory over Saracens as Mike Brown and Tom Williams complete the back-three.
Matt Hopper also returns alongside Jordan Turner-Hall in the centres. Rory Clegg has replaced Nick Evans in the fly-half position after Evans picked up a foot injury last weekend. Karl Dickson will start at scrum-half ahead of Care.
Mark Lambert starts at loosehead alongside Rob Buchanan and James Johnston in the front-row. Tomas Vallejos takes over from Olly Kohn at lock in tandem with captain George Robson.
Tom Guest is blindside with Nick Easter at eight. During Thursday's team run Chris Robshaw aggravated a knock originally picked up during last Saturday's match with Saracens; he has had to withdraw from the match squad where he is replaced by Luke Wallace.
Aston Croall, Marler and Will Collier cover the front-row, while Pete Browne returns in jersey 19, with Maurie Fa'asavalu providing cover in the back-row. Care provides cover at scrum-half with Benjamin Urdapilleta and Lowe providing cover from fly-half to full-back.
Meanwhile, Toulon have named Jonny Wilkinson and Matt Giteau in their starting line-up while former Aviva Premiership players Steffon Armitage, Dean Schofield, Carl Hayman, Sebastien Bruno and Eifion Lewis-Roberts all start for the Stade Félix Mayol showdown.
Toulon currently lie in third position in the Top 14, eleven points off second-placed Clermont.
Toulon: 15 Benjamin Lapeyre, 14 Alexis Palisson, 13 Mathieu Bastareaud, 12 Matt Giteau, 11 David Smith, 10 Jonny Wilkinson, 9 Sébastien Tillous-Borde, 8 Joe van Niekerk (capt), 7 Steffon Armitage, 6 Pierrick Gunther, 5 Dean Schofield, 4 Christophe Samson, 3 Carl Hayman, 2 Sebastien Bruno, 1 Eifion Lewis-Roberts.
Replacements: 16 Jean-Charles Orioli, 17 Romain Frou, 18 Davit Kubriashvili, 19 Joe El Abd, 20 Gabi Lovobalavu, 21 Luke Rooney, 22 Fabien Cibray, 23 Jocelino Suta.
Harlequins: 15 Mike Brown, 14 Tom Williams, 13 Matt Hopper, 12 Jordan Turner-Hall, 11 Ugo Monye, 10 Rory Clegg, 9 Karl Dickson, 8 Nick Easter, 7 Luke Wallace, 6 Tom Guest, 5 George Robson (capt), 4 Tomas Vallejos, 3 James Johnston, 2 Rob Buchanan, 1 Mark Lambert.
Replacements: 16 Aston Croall, 17 Joe Marler, 18 Will Collier, 19 Peter Browne, 20 Maurie Fa'asavalu, 21 Danny Care, 22 Benjamin Urdapilleta, 23 George Lowe.
Date: Friday, April 6
Kick-off: 20:45 (19:45 BST)
Venue: Stade Félix Mayol
Referee: George Clancy (Ireland)
Assistant referees: Dudley Phillips (Ireland), Carlo Damasco (Italy)