Melbourne - World No 4 Justin Thomas said he was like "a zombie" because of jetlag on Tuesday and complained that Australia's notorious flies were "destroying" him after his first practice round at the Presidents Cup.
The US team jetted into Melbourne on Monday on a private plane from the Bahamas, arriving later than expected after what captain Tiger Woods described as "a 26-hour ride in a luxurious tin can".
They got their first look at the Royal Melbourne course on Tuesday where they face Ernie Els' Internationals from Thursday, and American star Thomas said he was still struggling with the 16-hour time difference from the Bahamas.
"I feel like a zombie right now. I don't know what's going on," he said, with the flies that are so abundant in Australia during the summer adding to his woes.
"They're destroying me. I had a couple today that were on my face and wouldn't get off. It's definitely something I've never experienced."
Despite his difficulties acclimatising, Thomas said the Woods-led 12-man team was one big happy family, with even the wives and girlfriends getting on well.
"It's great, I think that the chemistry is something that we never struggled with and we all get along very well," he said.
"And I mean, even it goes into the wives and girlfriends and families, we all get along with each other. We all know each other, we play a lot of golf together."
Having camaraderie within the team is critical in the matchplay event that sees fourballs, foursomes and singles played across four days from Thursday.
But having families around is equally important, Thomas said.
"All of our significant others are some of our biggest supporting casts and are there for a lot of moments that everybody else doesn't see and the good and the bad," he said.
"So to be able to share really cool weeks like this, I think makes it a lot more special.
"And for me, especially, I'm very fortunate to have a great girlfriend that I love spending time with. So just to have these events and, for me alone, to see Australia and her as well, and then to get to do it together adds just another special moment to these team events."
The Americans are heavy favourites to win, having only lost once in the event's 25-year history - on the same Melbourne course in 1998.
Dustin Johnson, Xander Schauffele, Patrick Cantlay, Justin Thomas, Matt Kuchar, Webb Simpson, Bryson DeChambeau, Gary Woodland, Patrick Reed, Tony Finau, Tiger Woods, Rickie Fowler
Adam Scott (Australia), Marc Leishman (Australia), Cameron Smith (Australia), Hideki Matsuyama (Japan), Louis Oosthuizen (South Africa), Haotong Li (China), Abraham Ancer (Mexico), C.T. Pan (Taiwan), Adam Hadwin (Canada), Sungjae Im (South Korea), Joaquin Niemann (Chile), Byeong Hun An (South Korea)