USA head coach Eddie O'Sullivan is boosted by the return of Chris Wyles for their second Pool match, against Russia on Thursday.
Saracens full-back Wyles missed their opening tournament defeat to Ireland but is back to replace Blaine Scully in the number fifteen jersey.
US captain Todd Clever was left buoyed by his team's performance over the weekend but did feel concerned by an under-powered scrum display.
"I thought we played really well, and played with a lot of heart," said Clever.
"We're having trouble in the scrum. It's tough to say (what went wrong). It's maybe the timing. We got beat by the hit a few times.
"It's definitely something we have to focus on - that and some of the other set-pieces.
"Russia are a big side and it's definitely one of the things we need to nail down, to make sure we win our own ball and get possession."
Veteran centre Paul Emerick, who scored last weekend, added there was plenty of room to improve despite their decent showing against the Irish.
"A loss is a loss, it's not a win. We did some good things," he said.
"If we can keep doing those good things and then start fixing the little low things that we haven't been doing so well, Russia is going to be a good game for us.
"It's a pretty quick turnaround, but we'll keep the momentum going. Every game in the World Cup we want to give a spirited performance."
USA: 15 Chris Wyles, 14 Takudzwa Ngwenya, 13 Paul Emerick, 12 Andrew Suniula, 11 James Paterson, 10 Roland Suniula, 9 Mike Petri, 8 Nic Johnson, 7 Todd Clever (c), 6 Louis Stanfill, 5 Hayden Smith, 4 John van der Giessen, 3 Matekitonga Moeakiola, 2 Chris Biller, 1 Mike MacDonald.
Replacements: 16 Phil Thiel, 17 Shawn Pittman, 18 Scott LaValla, 19 Pat Danahy, 20 Tim Usasz, 21 Nese Malifa, 22 Blaine Scully.
Date: Thursday, September 15
Kick-off: 19:30 (07:30 GMT)
Venue: Stadium Taranaki, New Plymouth
Referee: Dave Pearson (England)
Assistant referees: Craig Joubert (South Africa), Carlo Damasco (Italy)
Television match official: Graham Hughes (England)