The 23-year-old hooker, a product of the club’s Academy, has played a key role in the successes of recent years, starting in both the Aviva Premiership and Amlin Challenge Cup final wins last season.
He forms part of a strong front row at Allianz Park this weekend, with Alex Corbisiero and Salesi Ma’afu also named in the starting 15.
Flanker Jon Fisher comes into the side to make his first appearance since suffering a foot injury in the pool game at Scarlets in early November.
Sam Olver, the 20-year-old, gets the nod at fly-half, with Stephen Myler among a strong set of replacements that also includes Calum Clark, Lee Dickson and James Wilson.
Christian Day, George Pisi and Ken Pisi are rested after picking up knocks in the 33-33 draw at Gloucester last Saturday.
Phil Dowson will captain Saints, who will be hoping to book a place in the March 22 showpiece at their Franklin’s Gardens home.
Meanwhile, Saracens have lock George Kruis among their replacements after his release by England.
Saracens: Ransom; Ellery, Bosch, Streather, Strettle; Mordt, Spencer; Gill, Saunders, Figallo; Itoje (c), Smith; De Jager, Hankin, Joubert.
Replacements: Spurling, Barrington, Alo, Kruis, Brown, Whiteley, Palamo, Fercu.
Saints: Tuala; Elliott, Stephenson, Waldouck, Collins; Olver, Fotuali’i; Corbisiero, Haywood, Ma’afu; Manoa, Ryder, Dowson (c), Fisher, Dickinson.
Replacements: Williams, E Waller, Denman, Nutley, Clark, Dickson, Myler, Wilson.