That doesn't, however, mean they aren't motivated to take the trophy for the first since 2017 when the 19th edition of the women's golf showdown begins Friday at Robert Trent Jones Golf Club.
"They want that trophy," Lewis said. "They'll talk about it, but I just think they need to enjoy themselves, to have fun and be relaxed."
Lewis got them a karaoke machine and had family send special messages to be delivered this week to help build camaraderie and smiles.
"This team is hungry and they want to have fun doing it," Lewis said. "When we're out on the golf course they're getting their work in. There is some seriousness, I promise, to what they're doing.
"I feel really good about where we're at for Friday morning."
The Americans lead the all-time rivalry 10-7 with one drawn, but Europe have taken the trophy in the past three editions of the event, winning thrillers by 14.5-13.5 and 15-13 before last year's 14-14 draw in Spain.
"I definitely think the US team is favored by quite a bit this year," Sweden's Anna Nordqvist said. "We all expect them to come out really strong. I feel pretty confident we have a really good team. We're all very excited for the challenge."
The Americans feature top-ranked Nelly Korda, a six-time LPGA winner this season, and second-ranked Lilia Vu, who won her first two majors in 2023. Overall the US women have six of the top 21 in the world rankings.
"The US team, they have been playing better than us on paper and world rankings, but I think this week is different," Spain's Carlota Ciganda said. "You have to make those putts to win and I think Europeans we all know how to do that.
"The US team is amazing - Nelly Korda, Lilia, great players - but I know we're going to put up a good fight. I believe in this team and I think we can do it."
The Europeans seek their first back-to-back triumphs on US soil.
"Looking forward to playing again on US soil," France's Celine Boutier said. "A win here would be amazing."
Four foursomes and four four-ball matches will be played on Friday and Saturday with 12 concluding singles matches on Sunday.
No pressure the USA way
Lewis said despite recent defeats and only two players who have won the Cup, the US team will stress not getting stressed.
"We put a lot of emphasis in what's going on in the team room, what's going on in the bus," Lewis said. "Whatever they need to do to help them stay relaxed.
"I don't feel any pressure when I'm in that team room... but the motivation is there. They're working hard and they want to win this thing.
"I don't see it as pressure. They don't, trust me. They're having lots of fun."
Vu is all right with that.
"We all kind of showed up and we're all really good players," Vu said. "We all have a fiery spirit and we all want to win, so I think that should be more than enough."
US teammate Allisen Corpuz says: "There's always going to be pressure. I just think it's learning to play through that and how to manage it."
For Lexi Thompson, who will retire at the end of the season, it's a US team-high seventh Cup appearance.
"Of course there's a little bit of unfinished business, but we know what we have to do," Thompson said. "We have to go out there and play some great golf."
Relaxed doesn't mean uninspired.
"I can feel the fire and the determination in the team room," American Andrea Lee said. "We all want to win that Cup back."