Grayson starts as Saints square up to London Irish
James Grayson will start at fly-half when Saints welcome London Irish to Franklin's Gardens on Friday night (kick-off 7.45pm).
Dan Biggar was available but has been given a breather ahead of his huge set of matches for Wales in the Six Nations.
Grayson will welcome the game time as he gets set to stand-in for Biggar during the next couple of months.
And the Academy graduate will get the chance to steer a Saints backline that also includes Taqele Naiyaravoro and Piers Francis, who both missed last weekend's win at Lyon.
Francis has recovered from concussion to line up alongside Rory Hutchinson, who will head off on Six Nations duty with Scotland on Sunday.
Ahsee Tuala moves from the wing to take the place of George Furbank at full-back, with Furbank, Fraser Dingwall, Courtney Lawes, Lewis Ludlam, Alex Moon and Alex Mitchell having headed off to join England.
In the pack, there are rare starts for loosehead prop Ben Franks and No.8 Mitch Eadie, meaning Teimana Harrison moves to seven.
Alex Coles and Api Ratuniyarawa form a new-look second row partnership.
Tom Collins has returned from his two-week suspension and takes his place among the replacements.
Reuben Bird-Tulloch (hand), Jamie Gibson (ankle), David Ribbans (ankle) and Matt Proctor (concussion) remain sidelined.
London Irish have handed a start to Saints legend Stephen Myler at fly-half, while another Northampton double-winner, Tom Stephenson, is named among the replacements.
Dave Porecki starts at hooker and is partnered in the front row by prop duo Harry Elrington and Sekope Kepu, with the latter making his first start for Irish.
Franco van der Merwe, who captains the side, is joined by Australia international Adam Coleman in the second row.
Matt Rogerson and Blair Cowan start at blindside and openside flanker respectively, with Fiji international Albert Tuisue wearing the No.8 jersey.
Ben Meehan and Myler combine in the half-backs.
Terrence Hepetema is named at inside centre and is joined in the midfield by Curtis Rona, who is at outside centre.
On the wings, Ollie Hassell-Collins and the returning New Zealand international Waisake Naholo are named, with James Stokes completing the line-up at full-back.
Saints: Tuala; Sleightholme, Hutchinson, Francis, Naiyaravoro; Grayson, Reinach; B Franks, Haywood, O Franks; Coles, Ratuniyarawa; Wood, Harrison (c), Eadie.
Replacements: Fish, Waller, Painter, Bean, Tonks, Taylor, Symons, Collins.
London Irish: Stokes; Naholo, Rona, Hepetema, Hassell-Collins; Myler, Meehan; Elrington, Porecki, Kepu; van der Merwe (c), Coleman; Rogerson, Cowan, Tuisue.
Replacements: Atkins, Dell, Hoskins, Mafi, Donnell, Phipps, Stephenson, Williams.