Rebecka Blomqvist's (26) second-half header and substitute Elin Rubensson's (30) 90th-minute penalty earned the third-ranked Swedes a 2-0 victory at Waikato Stadium on Wednesday and powered them into the next round as Group G winners.
Sweden had already secured qualification after seeing off South Africa and hitting five past Italy, allowing Gerhardsson the luxury of resting key players including Fridolina Rolfo (29) and Stina Blackstenius (27) and utilising his team's strength in depth.
"I think we will have many fresh players on Sunday, both in the starting 11 and the finishing 11," Gerhardsson, who made a sweeping nine changes for the Argentina match, told reporters.
"We always base it on the fact that we know the match on Sunday could last 120 minutes, and we have to make sure we can manage that. We're playing these matches with very little rest in between."
The Americans, pre-tournament favourites to win a third straight title, have been far from their scintillating best so far and scraped into the last 16 after a goalless draw with Portugal on Tuesday.
Sweden and the US will meet for the sixth World Cup in succession and the seventh time overall when they battle for a quarter-final spot in Sydney.
At the 2021 Tokyo Olympics, Sweden trounced the US 3-0 in the quarter-finals en route to the final and ended the Americans' unbeaten run spanning 44 games over 30 months.
"I rewatched that match recently and I don't think that's one of our best matches," Gerhardsson said. "I thought the expectations were quite low that we'd be able to achieve something like that.
"We were incredibly efficient... I think the result was excellent, but we were in trouble a few times. So it's possible that we have to be better on Sunday than we were there."
Gerhardsson led Sweden to a third-placed finish at the 2019 World Cup. They also won bronze in 2011 and 1991, and were runners-up to the US at the 2003 tournament.
"If you're going to go all the way, you're going to have to play this kind of opposition sooner or later," he said. "From a psychological perspective, we know we can beat them."
