Both players are listed as unavailable for selection, meaning Karl Wilkins and Rory Hutchinson have been handed starts against the league's bottom side.
Sam Matavesi comes in for James Fish at hooker, while Ehren Painter replaces Paul Hill.
Fish and Hill are among the replacements, along with Ollie Sleightholme, who returns from injury to take his place on the bench.
Tom Wood and Ahsee Tuala are now off the injured list, meaning they are set to be available in the weeks to come.
Lawes, Proctor, Piers Francis, Taqele Naiyaravoro and Teimana Harrison are listed as not considered for selection.
Saints secured a superb 36-20 win at Bristol Bears last Friday and will bid to back it up against a winless Bath outfit.
Bath have lost all eight of their league games this season, but they pushed Exeter Chiefs all the way at The Rec last Friday before losing 23-16.
Stuart Hooper's side for the trip to Northampton does not include influential flanker Miles Reid, who has been ruled out due to injury.
Orlando Bailey, Ruaridh McConnochie and Jonathan Joseph also miss out as they are all carrying slight knocks.
Will Butt will make his Premiership debut as the 21-year-old is named alongside Max Ojomoh at centre.
Tom Ellis comes in at six while Danny Cipriani starts at fly-half.
Bath opt for a 6:2 split on the bench as Mike Williams returns from suspension.
Tom Doughty, Max Clark, Juan Schoeman, Taulupe Faletau, Cameron Redpath, Tian Schoeman, Joe Cokanasiga, Ethan Staddon, Jaco Coetzee, Anthony Watson and Beno Obano are all unavailable due to injury.
Saints: Furbank; Freeman, Dingwall, Hutchinson, Skosan; Biggar, Mitchell; Waller, Matavesi, Painter; Ribbans, Moon; Wilkins, Ludlam (c), Augustus.
Replacements: Fish, Auterac, Hill, Ratuniyarawa, Coles, James, Litchfield, Sleightholme.
Bath: De Glanville; Rokoduguni, Butt, Ojomoh, Muir; Cipriani, Spencer; Boyce, Dunn, Stuart; McNally, Ewels (c), Ellis, Underhill, Bayliss.
Replacements: du Toit, Vaughan Rae, Williams, de Carpentier, Richards, Fox, Hamer-Webb.