Ayerza makes his first club appearance since the European quarter-final in Toulon last April as Tigers travel to Adams Park.
Williams comes in at fly-half and Hepetema makes his Aviva Premiership debut after two appearances as a replacement in Europe.
Tigers director of rugby Richard Cockerill, who returns to matchday duties at the end of his nine-game ban, selects Neil Briggs at hooker, David Mélé at scrum-half and brings Jamie Gibson in to the back row. There are also positional switches for Ed Slater and Logovi’i Mulipola.
Pablo Matera, the Argentina international back-rower signed following the loss of Tom Croft due a long-term knee injury, is included in the matchday squad for the first time.
Vereniki Goneva is sidelined after pulling a calf muscle in last week’s win over Benetton Treviso and Graham Kitchener is also ruled out this week.
Also unavailable due to injury are Anthony Allen, Gonzalo Camacho, Tom Croft, Scott Hamilton, Rob Hawkins, Ryan Lamb, Steve Mafi, Matt Smith, Scott Steele, Mathew Tait and Manu Tuilagi.
Dan Cole, Toby Flood, Geoff Parling, and Ben and Tom Youngs are retained by the England squad.
Leicester Tigers (v London Wasps, Adams Park, Sunday 2pm)
15 Niall Morris
14 Blaine Scully
13 Terrence Hepetema
12 Dan Bowden
11 Adam Thompstone
10 Owen Williams
9 David Mélé
1 Marcos Ayerza
2 Neil Briggs
3 Logovi’i Mulipola
4 Louis Deacon (c)
5 Ed Slater
6 Jamie Gibson
7 Julian Salvi
8 Thomas Waldrom
Replacements
16 George Chuter
17 Boris Stankovich
18 Fraser Balmain
19 Sebastian de Chaves
20 Jordan Crane
21 Pablo Matera
22 Miles Benjamin
23 Sam Harrison
For Wasps, Elliot Daly, Tom Palmer and Ashley Johnson return to the starting XV. Ben Jacobs is given the nod at centre, partnering captain Chris Bell, while Christian Wade returns from his time away with England to take his place on the wing.
London Wasps
15 Elliot Daly,
14 Christian Wade
13 Ben Jacobs
12 Chris Bell (c)
11 Josh Bassett
10 Andy Goode
9 Joe Simpson
1 Matt Mullan
2 Carlo Festuccia
3 Jake Cooper-Woolley
4 Tom Palmer
5 Kearnan Myall
6 Ashley Johnson
7 Guy Thompson
8 Ed Jackson
Replacements
16 Tom Lindsay
17 Simon McIntyre
18 Will Taylor
19 James Cannon
20 James Haskell
21 Charlie Davies
22 Joe Carlisle
23 Charlie Hayter
