Grant Seely replaces the former All Black in the starting line-up for Sunday's match at Adams Park.
Also returning to the starting line-up for this weekend's game are Welsh lock Steve Williams and England hooker Steve Thompson in the place of Rob Hunter and Dan Richmond.
Coach Wayne Smith said: "We know how difficult this game is going to be. None of these Premiership games are going to be easy while there are top three spots up for grabs."
Northampton Saints: 15 Nick Beal, 14 Bruce Reihana, 13 Peter Jorgensen, 12 John Leslie (captain), 11 Ben Cohen, 10 Paul Grayson, 9 Matt Dawson, 8 Mark Connors, 7 Budge Pountney, 6 Grant Seely, 5 Steve Williams, 4 Matt Lord, 3 Matt Stewart, 2 Steve Thompson, 1 Tom Smith.Replacements: 16 Dan Richmond, 17 Chris Budgen, 18 Rob Hunter, 19 Mark Soden, 20 Ian Vass, 21 James Brooks, 22 Mark Tucker.
Kick-off: 15.00 GMT
