Brooks, who played at scrum-half, fly-half and on the wing for Saints last season, will start the game at full-back.
Prop Chris Budgen will also make a position change to hooker.
The game, which will be played at La Teste at 6.30pm tomorrow, will mean debut Saints' starts for new signings Oriol Ripol and Steve Williams.
Northampton Saints
15 James Brooks
14 Mark Tucker
13 Chris Hyndman
12 John Leslie (cc)
11 Oriol Ripol
10 Paul Grayson
9 Matt Dawson
1 Tom Smith
2 Chris Budgen
3 Matt Stewart
4 Jon Phillips
5 Steve Williams
6 Rob Hunter
7 Budge Pountney (cc)
8 Mark Soden
Replacements:
Matt Price, Kelvin Todd, Robbie Morris, Ben Craig, Simon Hepher, Matt Richards, Liam Brown.
