Peter Richards comes in for the Welsh veteran, while in the centre Ayoola Erinle takes the place of Mark Denney.
Injury to England tighthead prop Will Green sees captain Craig Dowd switch sides in the scrum to cover, while Tim Payne starts at loosehead.
Hooker Trevor Leota – in the news this week for pulling out of Samoa's World Cup squad – starts after Phil Greening picked up a rib injury in last weekend's win against Leeds, with Jonny Barrett moving up to the bench.
Richard Birkett misses out in the second row with a slight knee injury, with Martin Purdy taking his place.
In the back row, Paul Volley switches from open to blindside, with Irishman Jonny O'Connor at No.7
O'Connor said: "I've never had the opportunity to play against Northampton, and therefore can't wait to get onto the field. I've heard from the boys that Franklin's Gardens is a great place to play rugby but also very tough. I expect it to be a battle."
England Under-21 international John Hart will play at No.8. James Haskell, who is the youngest Wasps player to start in the Zurich Premiership, is on the bench.
Coach Warren Gatland said ahead of the match: "Winning at Northampton is no easy task and this season will be no exception. I felt our defeat last season at Franklin’s Gardens was the only game where Wasps were well and truly beaten.
"We have yet to click into full gear, and if we are going to beat Saints we must up the tempo for this game. Saints are hungry for a win, we intend to keep them starved."
London Wasps: 15 Tom Voyce, 14 Shane Roiser, 13 Fraser Waters, 12 Ayoola Erinle, 11 John Rudd, 10 Mark Van Gisbergen, 9 Peter Richards, 8 John Hart, 7 Jonny O’Connor, 6 Paul Volley, 5 Martin Purdy, 4 Simon Shaw, 3 Craig Dowd (captain), 2 Trevor Leota, 1 Tim Payne.Replacements: 16 Rob Howley, 17 Jonny Barrett, 18 Mark Denney, 19 James Haskell, 20 George Skivington, 21 Ian Clarke, 22 Sean Phillips.
Kick-off: 15.00 (14.00 GMT)