It only gets more difficult from here on out for Team USA.

USA Basketball's bid for the 2019 FIBA World Cup gold medal in China hit a speed bump as five-time NBA champion San Antonio Spurs head coach Gregg Popovich's patriotic squad split a pair of pre-World Cup exhibition games with Australia on the Boomers' home turf.

Popovich and the Americans won a friendly in Anaheim, California, against Ricky Rubio, Marc Gasol, and Spain, then hit the Pacific theater with two tune-ups against Patty Mills and Australia. The first tilt saw new Boston Celtics point guard Kemba Walker lead the way in the win, recording a game-high 23 points. Saturday's bout, however, ended in a four-point loss. Walker scored 22 points in the defeat.

Walker's new teammate, Jaylen Brown, had more to say about Team USA's mindset as the World Cup approaches, per John Karalis of MassLive.com:

“I think there are infinite ways we can go. I just think that we have to go in the right direction,” Brown said. “Move forward in terms of our mindset, in terms of a mentality, and I think that’s bigger than whether we overreact or underreact. We got to change our mentality.”

“We’re playing for something bigger than ourselves,” Brown said. “Having an understanding of that and a humility of that is something we all have to have. I think we could have showed that a little bit better against Australia. We got to do a better job of having the right mentality, whether it’s an early game, whether it’s a back-to-back, whatever it is. We got to come out and be the aggressors, rather than the one being seeked [sic].”

The 22-year-old Jaylen Brown, a former third overall pick for the Celtics back in 2016, is making his USA Basketball debut under Popovich's stewardship. Previously, Brown played for the U18 squad, which won gold at the 2014 FIBA Americas Championship.