For winger Pisi, the Brighton Test marks a first World Cup cap, while Fotuali’i embarks on his second at scrum-half.
The Islanders are looking to maintain a perfect record that has seen them win all four meetings with the States to date - including a 21-16 victory in this year's Pacific Nations Cup.
The Pool B clash is a 12noon kick off and is being shown live on ITV.
SAMOA TEAM TO PLAY UNITED STATES
Rugby World Cup, Pool B
Brighton Community Stadium
Sunday, September 19th, 2015
Kick off 12noon
15 Tim Nanai-Williams (Ricoh Black Rams)
14 Ken Pisi (Northampton Saints)
12 Rey Lee Lo (Cardiff Blues)
11 Alesana Tuilagi (Newcastle Falcons)
10 Tusi Pisi (Suntory Sungoliath)
9 Kahn Fotuali'i (Northampton Saints)
2 Ole Avei (Bordeaux)
3 Anthony Perenise (Bristol)
4 Teofilo Paulo (Benetton Treviso)
5 Iosefa Tekori (Toulouse)
6 Teofilo Paulo (Benetton Treviso)
7 Jack Lam (Bristol)
8 Ofisa Treviranus (capt)(London Irish)
16 Viliamu Afatia (Agen)
17 Motu Matu’u (Hurricanes)
18 Census Johnston (Toulouse)
19 Faifili Levave (Toyota)
20 Alafoti Faosiliva (Bath)
21 Vavao Afemai (Samoa A)
22 Mike Stanley (unattached)
23 Fa'atoina Autagavaia (Nevers)
