The A's go into the game second in the table having played two thirds of their 30-game season, as they are ahead of former Championship-sides Plymouth and Birmingham Moseley in the standings.
Director of rugby Mark Lavery said: "They’ve a fantastic set up down there. The facilities are excellent, the pitch is perfect, and they know how to beat Ampthill; neither our firsts or our seconds have ever beaten them and they’re rightly favourites to win on Saturday.
“That said, they’ve lost a couple on the bounce and we’re on a nice little run, we’re beginning to go okay."
There’s a few adjustments for Ampthill in front; Matt Beasley [loosehead] and Reece Marshall [hooker], both on loan from Northampton, start on the front row former Tongan international Aleki Lutui [tighthead].
Mike Howard, on loan from Bedford, joins Paino Hehea in the second row, with Joe Bercis [openside], Matt Burke [blindside] and Maama Molitika  completing the A’s pack.
With duel-registered Saints scrum half Alex Mitchell away on England U20 duty, Ben Calder steps in at 9, partnering Joe Tarrant  at half-back; Steff Jones  and Sam Hanks  are paired in the centre with Sam Baker , Jonny Morgan  and Karim Lynch  completing Ampthill’s starting XV.