Out of the squad, however, are the injured trio of Matt Dawson (thigh), Budge Pountney (neck) and Peter Jorgensen (thumb).
Dawson's place will be filled by Ian Vass and Jorgensen's by Bruce Reihana. Oriol Ripol will come into the team on the wing and Darren Fox will continue to fill Pountney's boots.
The winners of tomorrow's game at Adams Park will go on to play Gloucester in the Zurich Premiership Final at Twickenham on May 31 to determine the title.
Head coach Wayne Smith said: "Making the Zurich Premiership semi-final is a reward for the fighting qualities of the players and management. We've fought for everything we've achieved, and we'll keep fighting.
"I like a play-off system. It's something we are used to in New Zealand. If you've shown the consistency needed to make the top three after 22 games, then you deserve a crack at the title. And that's what we'll do – have a crack."
Northampton Saints: 15 Nick Beal, 14 Oriol Ripol, 13 Bruce Reihana, 12 John Leslie (captain), 11 Ben Cohen, 10 Paul Grayson, 9 Ian Vass, 8 Andrew Blowers 7 Darren Fox, 6 Mark Connors, 5 Rob Hunter, 4 Matt Lord, 3 Robbie Morris, 2 Steve Thompson, 1 Matt Stewart.Replacements: 16 Matt Miles, 17 Chris Budgen, 18 Steve Williams, 19 Grant Seely, 20 James Brooks, 21 Mark Tucker, 22 Jon Sleightholme.
Kick-off: 18.00 BST (17.00 GMT)
